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Data Repository Item DR2011005
Late Cretaceous-early Cenozoic tectonic evolution of the southern California margin inferred from provenance of trench and forearc sediments
Carl E. Jacobson, Marty Grove, Jane N. Pedrick, Andrew P. Barth, Kathleen M. Marsaglia, George E. Gehrels, and Jonathan A. Nourse
Supplementary Text Explanation of palinspastic reconstruction Geologic summaries of forearc sampling areas and notes on individual samples Figures Figure Captions Figure DR1. Detrital zircon results – Catalina Schist and POR schist of San Emigdio Mts. Figure DR2. Figure 6 of main text showing NW-SE geographic subdivisions. Figure DR3. Zircon probability plots – All forearc units plotted by geographic location. Figure DR4. Zircon probability plots – Eocene forearc units plotted by geographic location. Figure DR5. QtFL Ternary diagram of forearc sedimentary units. Figure DR6. QmKP Ternary diagram of forearc sedimentary units. Figure DR7. QtFL contents of forearc sedimentary units on palinspastic base of Figure DR2. Figure DR8. QmKP contents of forearc sedimentary units on palinspastic base of Figure DR2. Figure DR9. LmLvLs contents of forearc sedimentary units on palinspastic base of Figure DR2. Figure DR10. Detrital zircon results – Rand Schists vs. Cambria and Pfeiffer slabs. Tables Table DR1. Summary data for samples of POR schists Table DR2. Summary data for samples of forearc sedimentary units Table DR3. Grouping of sedimentary samples by age and location Table DR4. Zircon U-Pb data Table DR5. Detrital modes of forearc samples by age groups Table DR6. Detrital modes of forearc samples by age and area groups
1
Explanation of Palinspastic Reconstruction
The palinspastic restoration utilized in this study closely follows that of Grove et al.
(2003). Details of the 2003 reconstruction are described in the Data Repository item
accompanying that publication. In this version, we made the following modifications:
1. Shift Pigeon Point Formation and Franciscan Complex and Upper Cretaceous sandstones
(Kuss of Hall, 1991) of the Pt. Sur area 46 km southeast along San Gregorio-Hosgri fault.
This represents a total of 156 km slip along the fault (Dickinson et al., 2005) as opposed
to 110 km used in the original map (Dickinson, 1996).
2. Separate western Transverse Ranges and Pine Mountain block along Pine Mountain fault.
Keep Pine Mountain block attached to southeast end of Sierra Madre Mountains. Move
western Transverse Ranges, Simi Hills, and Santa Monica Mountains (the latter two of
which were ignored by Grove et al., 2003) to locations shown by Bohannon and Geist
(1998). This requires a back-rotation of 106° compared to the value of ca. 80° indicated
by paleomagnetic data (Luyendyk et al., 1985). Use similar rotation for Channel Islands
and place adjacent to San Diego area.
3. Connect southeast end of Rinconada fault to northwest end of East Huasna fault (Hall et
al., 1995; Dickinson et al., 2005) rather than to northwest end of Nacimiento fault
(Dibblee, 1976; Powell, 1993). Restore northwest and southeast halves of Nacimiento
fault by 45 km of slip on combined Rinconada-East Huasna fault.
4. Reshape the San Rafael Mountains, La Panza Range, and Sierra Madre Mountains to
eliminate the gap along the Nacimiento fault.
5. Extend geology of the Peninsular Ranges south of that shown in Grove et al. (2003)
2
based on Grove et al. (2008; and references therein).
6. Add geology of northwestern Sonora based on Iriondo et al. (2005), Nourse et al. (2005),
and Nourse (personal communication, 2006).
7. Update geology of eastern Transverse Ranges based on Barth et al. (2008).
REFERENCES CITED
Barth, A.P., Anderson, J.L., Jacobson. C.E., Paterson, S.R., and Wooden, J.L., 2008a,
Magmatism and tectonics in a tilted crustal section through a continental arc, eastern
Transverse Ranges and southern Mojave Desert, in Duebendorfer, E.M., and Smith, E.I.,
eds., Field guide to plutons, volcanoes, reefs, dinosaurs, and possible glaciations in selected
areas of Arizona, California, and Nevada: Geological Society of America Field Guide 11, p.
101–117, doi: 10.1130/2008.fld011(05).
Bohannon, R.G., and Geist, E.L., 1998, Upper crustal structure and Neogene tectonic
development of the California continental borderland: Geological Society of America
Bulletin, v.110, p. 779–800.
Dibblee, T.W., Jr., 1976, The Rinconada and related faults in the southern Coast Ranges,
California, and their tectonic significance: U.S. Geological Survey Professional Paper 981,
55 p.
Dickinson, W.R., 1996, Kinematics of transrotational tectonism in the California Transverse
Ranges and its contribution to cumulative slip along the San Andreas transform fault system:
Boulder, Colorado, Geological Society of America Special Paper 305, 46 p.
Dickinson, W.R., Ducea, M., Rosenberg, L.I., Greene, H.G., Graham, S.A., Clark, J.C., Weber,
G.E., Kidder, S., Ernst, W.G., and Brabb, E.E., 2005, Net dextral slip, Neogene San
3
Gregorio–Hosgri fault zone, coastal California: Geologic evidence and tectonic implications:
Geological Society of America Special Paper 391, 43 p, doi: 10.1130/2005.2391.
Grove, M., Jacobson, C.E., Barth, A.P., and Vucic, A., 2003, Temporal and spatial trends of Late
Cretaceous–early Tertiary underplating of Pelona and related schist beneath southern
California and southwestern Arizona, in Johnson, S.E., Patterson, S.R., Fletcher, J.M., Girty,
G.H., Kimbrough, D.L., and Martin-Barajas, A., eds., Tectonic evolution of northwestern
Mexico and the southwestern USA: Geological Society of America Special Paper 374, p.
381-406.
Grove, M., Bebout, G.E., Jacobson, C.E., Barth, A.P., Kimbrough, D.L., King, R.L., Zou, H.,
Lovera, O.M., Mahoney, B.J., and Gehrels, G.G., 2008, The Catalina Schist: Evidence for
middle Cretaceous subduction erosion of southwestern North America, in Draut, A.E., Clift,
P.D., and Scholl, D.W., eds., Formation and applications of the sedimentary record in arc
collision zones: Geological Society of America Special Paper 436, p. 335–362.
Hall, C.A., Jr., 1991, Geology of the Point Sur-Lopez Point region, Coast Ranges, California: A
part of the Southern California allochthon: Boulder, Colorado, Geological Society of
America Special Paper 266, 40 p.
Hall, C.A., Jr., Sutherland, M.J., and Ingersoll, R.V., 1995, Miocene paleogeography of west-
central California, in Fritsche, A.E., ed., Cenozoic paleogeography of the western United
States – II: Pacific Section, SEPM (Society for Sedimentary Geology), Book 75, p. 85–112.
Iriondo, A., Martínez-Torres, L.M., Kunk, M.J., Atkinson Jr., W.W., Premo, W.R., and
McIntosh, W.C., 2005, Northward Laramide thrusting in the Quitovac region, northwestern
Sonora, Mexico: Implications for the juxtaposition of Paleoproterozoic basement blocks and
the Mojave-Sonora megashear hypothesis, in Anderson, T.H., Nourse, J.A., McKee, J.W.,
4
and Steiner, M.B., eds., The Mojave-Sonora megashear hypothesis: Development,
assessment, and alternatives: Geological Society of America Special Paper 393, p. 631-669.
Luyendyk, B.P., Kamerling, M.J., Terres, R.R., and Hornafius, J.S., 1985, Simple shear of
southern California during Neogene time suggested by paleomagnetic declinations: Journal
of Geophysical Research, v. 90, p. 12,454–12,466.
Nourse, J.A., Premo, W.R., Iriondo, A., and Stahl, E. R., 2005, Contrasting Proterozoic basement
provinces near the truncated margin of Laurentia, northwestern Sonora-Arizona border
region, in Anderson, T.H., Nourse, J.A., McKee, J.W., and Steiner, M.B., eds., The Mojave-
Sonora megashear hypothesis: Development, assessment, and alternatives: Geological
Society of America Special Paper 393, p. 123-182.
Powell, R.E., 1993, Balanced palinspastic reconstruction of pre-late Cenozoic paleogeology,
southern California, in Powell, R.E., Weldon, R.J., and Matti, J.C., eds., The San Andreas
fault system: Displacement, palinspastic reconstruction, and geologic evolution: Boulder,
Colorado, Geological Society of America Memoir 178, p. 1-106.
5
Geologic Summaries of Forearc Sampling Areas and Notes on Individual Samples
INTRODUCTION
Here we provide background information for all forearc samples analyzed in this study
excluding those from the Peninsular Ranges, which will be described elsewhere by M. Grove et
al. (also, see Grove et al., 2003, for a review of the Pelona-Orocopia-Rand schist localities). The
descriptions are organized alphabetically by geographic area (see Figs. 1, 2, and 6 of the main
text for locations). The areas were defined in large measure by using major faults as boundaries.
We also took into account spacing of samples and number of analyses per sample; i.e., a larger
number of results allows for finer subdivision. Note that some areas expose rocks representing
only a limited portion of the Late Cretaceous to Eocene stratigraphic range considered here,
whereas others include a much more complete record of sedimentation. For this reason, as well
as owing to the constraints of time and access, the number of samples analyzed per area ranges
widely (from one to ten). In general, the emphasis of our summaries is on the stratigraphy of the
sampled formations. However, in some cases we provide additional stratigraphic, structural,
petrologic, or other information deemed relevant to understanding the geologic context of the
samples.
Because of the reconnaissance nature of this study, and the large area of coverage, it was
not possible for us to conduct an exhaustive literature review for each sampling locality. Critical
from our perspective was to have the most up-to-date age assignments and a correct assessment
of tectonic setting (e.g., there has been debate as to whether some of the areas we sampled
belong to the Salinian or Nacimiento blocks). We thus tended to focus on the literature of the last
three to four decades and on review papers. This led us to pass over many “classic”
6
investigations that paved the way for later work. We apologize for the failure to cite these and
many other important works on this region.
Following the geologic overview of each area, we include a listing of samples analyzed
from that area. For all samples, we indicate the formal or informal stratigraphic name and age
(we use the geologic time scale of Walker and Geissman, 2009). Various additional pieces of
information are provided for most samples depending on circumstances. Items potentially
included, and the order of listing, are:
1. Stratigraphic name.
2. Map references. In many cases we used detailed geologic maps, such as those from the
Dibblee Foundation or the U.S. Geological Survey, to help locate samples. We indicate those
where relevant and also list the unit symbol from such maps.
3. Proximity to localities described by others.
4. Descriptions that help place the sample in a geographic context.
5. Depositional environment.
6. Age.
Name and age are considered most important and are placed first and last, respectively, to make
them easy to find in the text.
GEOGRAPHIC AREAS
Atascadero
Upper Cretaceous strata within the Nacimiento block in the southern Santa Lucia Range
have been assigned to the Atascadero Formation (Hart, 1976, 1977; Seiders, 1982). These rocks
were deposited upon the Upper Jurassic-Lower Cretaceous Toro Formation and associated Coast
7
Range ophiolite, but locally are in fault contact with those units or the Franciscan Complex
which underlies them. The oldest units depositionally overlying the Atascadero Formation are
Oligocene in age.
A relatively intact section of the Atascadero Formation approximately 1500 m thick is
present in the Paradise Valley area (Hart, 1976). The lower part of the Paradise Valley section is
dominated by mudstone. Lesser turbidite sandstones with relatively low contents of K-feldspar
(0.5-10%) are also present. The upper part of the Paradise Valley section is characterized by
thick, massive sandstone beds with 20-25% K-feldspar and interbedded turbidite sequences.
Outside the Paradise Valley area, the Atascadero Formation is highly sheared and dismembered,
making correlations and determination of original stratigraphic thickness difficult. Nonetheless,
Hart (1976) estimated an aggregate thickness for the formation of 2-3 times that exposed in the
Paradise Valley area.
Much of the Atascadero Formation consists of turbidite and related sequences that likely
were deposited in a deep-sea fan complex and associated basin plain setting (e.g., unit Ka of
Seiders, 1982). Part of the formation, however, may have been deposited in a shelf environment
(unit Kaps of Seiders, 1982).
The Atascadero Formation is sparsely fossiliferous and its age is not well constrained.
The basal part of the Paradise Valley sequence is probably Cenomanian or Turonian (Hart,
1976), but much of the rest of the unit is apparently early to late Campanian (Hart, 1976; Seiders,
1982).
Dickinson et al. (2005) noted that sandstones in the Atascadero Formation overlap in
composition with those from the Salinian block, but on average have higher contents of lithic
grains and lower proportions of K-feldspar. Based on this and other characteristics, they
8
considered the Atascadero Formation to be correlative with the Pigeon Point Formation. This is
reasonably consistent with our limited numbers of detrital zircon analyses (39 ages from the
Pigeon Point Formation and 55 analyses from the coeval [Campanian] part of the Atascadero
Formation). On the other hand, Elder and Saul (1993), reported distinct faunal differences
between the Atascadero and Pigeon Point Formations.
99-68
Atascadero Formation. Unit Ka of Hart (1976); unit Kas of Dibblee (2004); correlative with unit
Ka of Seiders (1982). Probably Campanian (Seiders, 1982).
YM1
Atascadero Formation. Unit Kaps of Seiders (1982); unit Kas of Dibblee (2006a). Equivalent to
locality Y-160 of Seiders and Cox (1992). Probably lower or middle Campanian (Seiders, 1982).
YM3
Atascadero Formation. Unit Kaps of Seiders (1982); unit Kas of Dibblee (2006a). Probably
lower or middle Campanian (Seiders, 1982).
YM4
Atascadero Formation. Unit Ka1 of Hart (1976); unit Kash of Dibblee (2004). Probably
Cenomanian or Turonian (Hart, 1976).
YM5
Atascadero Formation. Unit Ka4 of Hart (1976); unit Kas of Dibblee (2004); correlative with unit
Ka of Seiders (1982). Probably Campanian (Seiders, 1982).
Ben Lomond Mountain
We sampled a locality (BP-78-1D of Seiders and Cox, 1992) that Brabb (1989) placed in
9
the Locatelli Formation, but that Seiders and Cox (1992) considered to be within the basal part of
the overlying Butano Sandstone. The Locatelli Formation comprises a siltstone-dominated
sequence up to 270 m thick in nonconformable contact with the crystalline basement of Ben
Lomond Mountain (Clark, 1981). It is considered to be Paleocene (Ynezian) in age (Clark,
1981). The lower to middle Eocene Butano Sandstone, which may be as much as 3,000 m in
thickness, sits unconformably above the Locatelli Formation in some places, but elsewhere was
deposited directly on crystalline basement (Clark, 1981; Nilsen, 1985; McDougall, 1989; Seiders
and Cox, 1992). Seiders and Cox (1992) assigned locality BP-78-1D to the Butano Sandstone
based on an early Eocene foraminiferal age from immediately underlying mudstone (R.Z. Poore,
written communication, 1989, in Seiders and Cox, 1992). Because of the broad early to middle
Eocene age of the Butano Sandstone as a whole, we include this sample in the Eocene group,
along with middle Eocene samples (IR3 and IR4) from the Indians Ranch area of the Northern
Santa Lucia Range. Note, however, that sample BB1, coming as it does from the lowermost part
of the Butano Sandstone, could actually be closer in age to the Carmelo Formation of Point
Lobos, which is most likely early Eocene in age (see section on Point Lobos), and which we
have included in the middle Maastrichtian to Paleocene age group.
BB1
Butano Sandstone. Equivalent to locality BP-78-1D of Seiders and Cox (1992). Lower Eocene.
Cajon Pass
This region includes a small tract of mostly marine sandstone and shale on the northeast
side of the San Andreas fault. Stratigraphic thickness is 500 m according to Dibblee (1967), but
125 m according to Kooser (1980). Dibblee (1967) correlated these strata with the San
10
Francisquito Formation of the Warm Springs Mountain and Valyermo areas. More recent
workers, however, have tended to view the Cajon Pass beds and the type San Francisquito
Formation as separate units (Kooser, 1982; Saul, 1983; Nilsen, 1987), at least partly because they
were widely separated prior to slip on the San Andreas fault. Age is controversial but most likely
Maastrichtian based on regional stratigraphic relations (Vedder et al., 1983; Grove, 1989, 1993;
Dickinson et al., 2005) and the presence of fossil plesiosaur vertebrae (Kooser, 1982, 1985; Saul,
1983; Lucas and Reynolds, 1993; Gasparini et al., 2003; Kooser, personal communication,
2007).
SF3
“San Francisquito Formation.” Unit Tsf of Dibblee (2003). Probably Maastrichtian.
Cambria
The central California coastal region in the vicinity of the town of Cambria is underlain
by a distinctive sedimentary sequence referred to informally as the “Cambria slab” (Howell et
al., 1977; Smith et al., 1979; Becker and Cloos, 1985; Underwood and Howell, 1987). These
rocks sit atop and within the Franciscan Complex and were originally considered to be part of the
latter (Hsü, 1969). Subsequent workers, however, have tended to view the Cambria slab as the
remnants of a ponded basin on the inner trench wall (i.e., a trench-slope basin). The unit is
dominated by massive beds of medium- to coarse-grained sandstone (Howell et al., 1977).
Rhythmically interbedded siltstone and sandstone occur in lesser abundance. Conglomerate and
shale are rare. Howell et al. (1977) described a homoclinal, eastward-dipping section, with
thickness of ~4 km, extending southeastward from Abalone Cove. A more limited,
northeastward-dipping section is present to the north of Abalone Cove and seems to be separated
11
from the southern section by a fault. Underwood and Howell (1987) observed a significant
difference in thermal maturity across the fault (lower-temperature to the north), suggesting a
vertical displacement of up to 2 km.
The age of the Cambria slab is not well constrained from fossil evidence. It is generally
assigned broadly to the Upper Cretaceous (Hall, 1974; Howell et al., 1977; Hall et al., 1979;
Smith et al., 1979; Becker and Cloos, 1985), although Page (1982, p. 1709) suggested that a
Campanian age is most likely. The latter is consistent with our detrital zircon ages; i.e., the
average of the three youngest ages obtained for each of our three samples (excluding one
anomalously young result of 74 ± 5 Ma) are 84, 85, and 87 Ma, respectively.
The Pfeiffer Beach slab of Underwood (1977) and the Pfeiffer slab of Hall (1991) in the
Point Sur area and the Point San Luis slab southwest of San Luis Obispo exhibit some
similarities to the Cambria slab and have likewise been interpreted as trench-slope basins
(Howell et al., 1977; Underwood, 1977; Smith et al., 1979; see also the section on the Point Sur
area). However, studies of thermal maturity indicate that the slabs at Point Sur and Point San
Luis were subjected to significantly higher peak temperatures than the Cambria slab (Underwood
et al., 1995; Underwood and Laughland, 2001). This has been taken as evidence that the Point
Sur and Point San Luis units are more likely to represent subducted sediments of the Franciscan
Complex than trench-slope basins.
99-66A
Cambria slab. Base of section north of Abalone Cove. Position relative to samples 03-01 and 03-
03 is uncertain. Probably Campanian.
03-01
Cambria slab. Upper part of the homoclinal, eastward-dipping section located south of Abalone
12
Cove. Probably Campanian.
03-03
Cambria slab. Lower part of the homoclinal, eastward-dipping section located south of Abalone
Cove. Probably Campanian.
Del Puerto Canyon
Del Puerto Canyon is situated at the northern end of the northeast flank of the Diablo
Range. This area lies within the type Great Valley Group of the Sacramento and San Joaquin
Valleys east of the San Andreas fault (Ojakangas, 1968; Dickinson and Rich, 1972; Ingersoll,
1979, 1982; Linn et al., 1992; DeGraaff-Surpless et al., 2002). One sample was collected from
this region to serve as a comparison to our main sample set from southern California and central
California west of the San Andreas (i.e., the Salinian and Nacimiento blocks).
The Great Valley Group represents a classic forearc basin sequence deposited
contemporaneously with the accumulation of the Franciscan Complex and emplacement of the
Sierra Nevada magmatic arc. The western (distal) part of the sequence was deposited on the
Coast Range ophiolite and is as old as latest Jurassic (see Surpless et al., 2006, and Wright and
Wyld, 2007, for a discussion of the age of the base of the distal Great Valley Group). The eastern
margin of the basin migrated eastward with time onlapping the eroded Sierran arc. The oldest
exposures along the eastern margin of the basin are early Late Cretaceous in age.
The oldest part of the Great Valley Group was formed by the erosion of an arc collisional
terrane formed during the Nevadan orogeny (Ingersoll, 1983). This basal sequence is rich in
lithic fragments and exhibits a high ratio of plagioclase to K-feldspar. Younger parts of the
sequence were formed by erosion of progressively more eastward and deeper levels of the arc
13
(Ingersoll, 1983). The middle to Upper Cretaceous parts of the sequence are noticeably arkosic in
composition, similar to the compositions of upper Cretaceous sandstones analyzed in this study
from the less-well-preserved southern extension of the Great Valley basin (this study; Gilbert
and Dickinson, 1970; Hart, 1976; Lee-Wong and Howell, 1977; Grove, 1993; Dickinson, 1995;
Dickinson et al., 2005).
99-66A
Rumsey petrofacies of the Great Valley Group. Equivalent to Stop 1.6 of Ingersoll et al. (1999).
Inner fan facies. Campanian.
Indians Ranch
The Indians Ranch area lies within the northern Santa Lucia Range of the central
California coastal region. Upper Cretaceous to Paleocene sedimentary rocks of this area are
inferred to have been deposited within the mid-canyon segment of an ancient submarine canyon
incised into Salinian basement (Graham, 1979a; Ruetz, 1979; Anderson et al., 2006). These units
have a maximum thickness of ~2 km and a width of ~15 km, indicating a scale comparable to
that of the modern Monterey submarine canyon of the central California borderland. Eocene and
younger sedimentary units sit with angular unconformity upon the Cretaceous-Paleocene section.
IR1
Unnamed Upper Cretaceous sandstone. Inferred to be middle to upper Maastrichtian based upon
correlation with fossiliferous units in the Lake Nacimiento area (Saul, 1986; Seiders, 1986;
Sliter, 1986) and on latest Cretaceous intrusive and cooling ages of the depositionally underlying
Salinian crystalline basement (Kidder et al., 2003; Barbeau et al., 2005).
14
IR3
Assigned to the conglomerate member of the Church Creek Formation by Graham (1979b) but to
the Reliz Canyon Formation by Seiders and Joyce (1984). Middle Eocene in either case.
Equivalent to fossil locality 14-87 of Graham (1979b); between localities CP433 and CP459 of
Seiders and Cox (1992).
IR4
Base of the mudstone member of the Church Creek Formation of Graham (1979b). Equivalent to
the Lucia Shale member of the Reliz Canyon Formation of Dibblee (2006b). Middle Eocene.
IR5
Merle Formation. Upper part of unit 2 (Ruetz, 1979; Anderson et al., 2006). Paleocene.
La Panza Range
The term “La Panza Range” is used here to include both the range of that name and a
geologically similar region surrounding Santa Margarita Lake southwest of the La Panza fault (in
formal geographic nomenclature, the latter area is actually part of the southern Santa Lucia
Range). In both areas, strata of probable Maastrichtian age (Grove, 1993) sit nonconformably
above crystalline basement of the Salinian block, including Late Cretaceous granodiorite, quartz
monzonite, and related intrusive rocks and Precambrian gneiss (Grove, 1989, 1993; Vedder et
al., 1983, 1986; Seiders and Cox, 1992). The Santa Margarita Lake section is thicker and more
complete than that in the La Panza Range sensu stricto (Grove, 1989, 1993). In the former area,
the basal part of the section comprises various bathyal facies of a submarine fan complex. These
units grade upward to a shallow marine to nonmarine section, which in turn is overlain by a
transgressive marine sequence capped by thinly-bedded turbidites. In the La Panza Range (Pozo
15
Grade sequence), the lowermost beds consist of nonmarine conglomerate and sandstone that
grade upward to a submarine fan complex. The Pozo Grade section is inferred to correlate with
the middle and upper parts of the section around Santa Margarita Lake (Grove, 1989, 1993).
Ages are believed to be middle to late Maastrichtian (Saul, 1986; Seiders, 1986; Sliter, 1986).
In both the La Panza Range and Santa Margarita Lake area, Upper Cretaceous beds pass
upward to the southeast into a thick Paleogene sequence, although the exact location of the
Cretaceous-Paleogene boundary is not well constrained (Chipping, 1972; Vedder et al., 1988,
1989a, 1989b; Grove, 1993; Dickinson, 1995).
PZ1
Unnamed Upper Cretaceous sandstone. Unit Kuc(?) of Vedder et al. (1986); unit Kcg of Dibblee
(2006c). From the basal, nonmarine sequence. A few tens of meters stratigraphically above
locality PZ-1 of Grove (1989) along Pozo Grade. Probably middle to upper Maastrichtian.
We determined ages for nine zircons from this sample. One is late early Proterozoic in
age. The other eight cluster at 84–74 Ma with a mean and median of 78 Ma. We take the strong
grouping of ages to indicate that this sediment was derived largely from the local granodiorite
basement. The average age for the Cretaceous detrital zircons from this sample is
indistinguishable from the 78–76 Ma ages obtained by Mattinson (1990) for plutons in the La
Panza Range and other parts of southeastern Salinia.
PZ3
Unnamed Upper Cretaceous sandstone. Unit Ku of Vedder et al. (1986); unit KTss of Dibblee
(2006c). From the base of the upper marine part of the section along Pozo Grade. Equivalent to
locality PZ-4 of Grove (1989). Probably middle to upper Maastrichtian.
16
PZ4
Unnamed Paleogene sandstone. Unit Tus of Vedder et al. (1986); unit KTsh of Dibblee (2006c).
Located along the Salinas River at the confluence with American Canyon. Deposited in a
submarine fan environment (Vedder et al., 1986). Equivalent to locality PZ-539 of Seiders and
Cox (1992). Age is undifferentiated Paleocene or Eocene (Vedder et al., 1986; Seiders and Cox,
1992). Despite this uncertainty, we collected this sample because of its position approximately
midway within the continuous stratigraphic section extending from known Upper Cretaceous
rocks of the La Panza area through Eocene rocks within the Sierra Madre Mountains to the
southeast. For the purposes of plotting results, we included this sample within the mid-
Maastrichtian-Paleocene group.
SML1
Unnamed Upper Cretaceous sandstone. Unit Ku of Vedder et al. (1986); unit Ksg of Dibblee
(2006c). From the lower, deep marine part of the section around Santa Margarita Lake.
Equivalent to locality SML-3 of Grove (1989). Probably middle to upper Maastrichtian.
Northwest Santa Lucia Range
Upper Cretaceous sedimentary rocks deposited on Salinian basement are exposed in a
narrow strip along the western margin of the northern Santa Lucia Range from north of Point Sur
to south of Slates Hot Springs (Esalen). These units belong to the Upper Cretaceous eastern
facies of Hall (1991). Broadly similar Upper Cretaceous units are exposed ~10 km inland of the
southern part of the coastal strip, but are described separately in the section on the Indians Ranch
area.
Hall (1991) reviewed previous paleontologic studies indicating a Maastrichtian or
17
Campanian to Maastrichtian age for the Upper Cretaceous eastern facies. Based on intrusive and
metamorphic cooling ages of the Salinian basement, Kidder et al. (2003), Barbeau et al. (2005),
and Dickinson et al. (2005) interpreted these units to be middle or late Maastrichtian in age. We
accept the latter assignment.
Hall (1991) correlated the Upper Cretaceous eastern facies with the Pigeon Point
Formation. In contrast, Grove (1989, 1993) and Dickinson et al. (2005) concluded from
sandstone petrology, conglomerate clast assemblages, and biostratigraphy that the Pigeon Point
Formation is more typical of the Upper Cretaceous sequences of the Nacimiento block. We
accept the latter view, which is more consistent with our detrital zircon data.
Our three samples from this area are stratigraphically equivalent to the three samples of
“Upper Cretaceous cover units” analyzed for detrital zircons by Barbeau et al. (2005). In fact,
their sample ESALEN and our sample ES1 were collected within ~75 m of each other.
Additional Upper Cretaceous units (Upper Cretaceous western facies of Hall, 1991) are
exposed in this region in the Nacimiento block to the west of the San Gregorio-Hosgri fault
system (referred to as the Sur fault zone in this area; Howell et al., 1977; Hall, 1991; Dickinson
et al., 2005). The latter units are described in the section on the Point Sur area and are probably
slightly older than the adjacent Upper Cretaceous strata northeast of the Sur fault zone.
ES1
Unnamed Upper Cretaceous sandstone. Part of Upper Cretaceous eastern facies of Hall (1991);
equivalent to Upper Cretaceous cover units of Barbeau et al. (2005). Same as locality ESALEN
of Barbeau et al. (2005). Probably middle to upper Maastrichtian.
PS1
Unnamed Upper Cretaceous sandstone. Part of Upper Cretaceous eastern facies of Hall (1991);
18
equivalent to Upper Cretaceous cover units of Barbeau et al. (2005). Equivalent to locality PS-
399 of Seiders and Cox (1992). Probably middle to upper Maastrichtian.
PT1
Unnamed Upper Cretaceous sandstone. Part of Upper Cretaceous eastern facies of Hall (1991);
equivalent to Upper Cretaceous cover units of Barbeau et al. (2005). Equivalent to locality PT-
400 of Seiders and Cox (1992). Probably middle to upper Maastrichtian.
Orocopia Mountains
The lower Eocene Maniobra Formation of the north-central and northeastern Orocopia
Mountains comprises ~1500 m of mostly marine sediment deposited on Mesozoic granitic rocks
(Crowell and Susuki, 1959; Advocate et al., 1988). The formation includes a thin basal
nonmarine to shallow-marine transgressive unit of sandstone and conglomerate overlain by fine-
grained slope deposits. The above units, as well as the crystalline basement, were incised by a
submarine channel, which extended from nearshore to bathyal depths within a distance of only 3
km along the axis of the channel. The channel was filled by interfingering mudstone and
sandstone units. The short distance from shoreline to abyssal depths, combined with various
aspects of the facies distributions, suggests that the basin was fault controlled (Advocate, et al.,
1988). Chipping (1972) considered that the Orocopia area was positioned at the head of a
submarine fan complex that extended to the southwest into areas that are now part of the Pine
Mountain block, Sierra Madre Mountains, Santa Ynez Mountains, etc. (see also Thompson,
1988). Our detrital zircon results are consistent with this view.
OR432
Maniobra Formation. Sandstone from the uppermost part of the canyon-fill complex. Lower
19
Eocene.
OR433
Maniobra Formation. Sandstone from the middle of the canyon-fill complex. Lower Eocene.
Pigeon Point
The Upper Cretaceous Pigeon Point Formation is exposed in a narrow strip along the
Pacific Coast ~40 km northwest of Santa Cruz on the west side of the San Gregorio-Hosgri fault.
The unit was described and named by Hall et al. (1959). Our sampling was based on the mapping
and stratigraphic interpretations of Howell and Joyce (1981). The latter workers inferred a
composite stratigraphic section with thickness of 3,300 m based on correlation of a major
conglomerate unit across a fault boundary between the northern and southern parts of the area.
The formation may be depositional upon a ca. 90-86 felsite inferred to have been intruded into
the Franciscan Complex (Ernst, personal communication, 2010). The top of the formation is not
exposed. Inferred depositional environments from base to top are middle fan, inner fan, feeder
channel, slope, and shelf.
Hall et al. (1959) interpreted parts of the section as Campanian and probably
Maastrichtian. They considered that other parts might be older, but no older than Coniacian.
More recent paleontologic studies, however, suggest a mostly early to middle Campanian age for
the sequence (Elder and Saul, 1993, 1996; Squires and Saul, 2003, Saul and Squires, 2008). We
determined a total of 39 zircon ages from the three samples. The youngest age, 73.1 ± 3.6 Ma,
comes from the sample from the base of the exposed section (Sample PP3), which would imply
an age no older than late Campanian. However, the error is relatively large, the next youngest
age from any of the other samples is 80.3 ± 5.0 Ma (Sample PP1), and the next youngest age
20
from Sample PP3 is 85.4 ± 5.1 Ma. Four additional grains from Sample PP3 yielded ages in the
range of 90–86 Ma. Hence, the zircon ages are in reasonable agreement with the work of Elder
and Saul (1993) and Squires and Saul (2003).
Although the depositional basement of the Pigeon Point Formation is not exposed, many
workers have inferred that the unit belongs to the Salinian terrane (Clark and Brabb, 1978;
Howell and Vedder, 1978; Clark, 1981; Howell and Joyce, 1981; Champion et al., 1984).
However, the Campanian (or older) depositional ages, sandstone petrology, and conglomerate
clast compositions are more typical of Upper Cretaceous sedimentary sequences of the
Nacimiento block than of the Upper Cretaceous sequences of the Salinian block, which appear to
be no older than Maastrichtian (Lee-Wong and Howell, 1977; Grove, 1989, 1993; Dickinson et
al., 2005). In particular, Dickinson et al. (2005) correlated the Pigeon Point Formation with the
Atascadero Formation of the Nacimiento block. Our limited detrital zircon results show a
reasonable match between the two. Elder and Saul (1993), however, noted distinct faunal
differences between the Atascadero and Pigeon Point Formations.
Champion et al. (1984) inferred from paleomagnetic data that the Pigeon Point Formation
was deposited 25° south of its present location. Kodama and Davi (1995) concluded that part of
this anomaly could be explained by compaction shallowing, although they still argued for ~15°
of northward transport since the Late Cretaceous. In contrast, Butler et al. (1991) and Dickinson
and Butler (1998) argued that the Nacimiento and Salinian blocks have undergone no significant
translation other than that related to the Neogene San Andreas system.
PP1
Pigeon Point Formation. Near Pigeon Point – Stop 3 of Howell and Joyce (1981). From a
medium- to coarse-grained sandstone bed in a region dominated by relatively fine-grained
21
inferred slope deposits in the upper, but not uppermost, part of the section. Probably lower to
middle Campanian.
PP2
Pigeon Point Formation. Pebble Beach – north end of Stop 2 of Howell and Joyce (1981).
Lithofacies B of Howell and Joyce (1981); thick-bedded to massive sandstones of inferred supra-
fan origin. Probably lower to middle Campanian.
PP3
Pigeon Point Formation. Pescadero Point – Stop 1 of Howell and Joyce (1981). Massive
sandstone bed in a region dominated by thin-bedded turbidites in the lowermost part of the
exposed section. Inferred to be middle-fan levee, overbank, and/or interchannel deposits (Howell
and Joyce, 1981). Probably lower to middle Campanian.
Pine Mountain Block
We define the Pine Mountain block as the region bounded by the Big Pine, Pine
Mountain, San Andreas, and San Gabriel faults. In this area, we sampled the Eocene Juncal
Formation, which correlates with Eocene units of the Sierra Madre Mountains, but represents a
somewhat more proximal submarine fan facies (inner-fan facies; Jestes, 1963; Chipping, 1972;
Thompson, 1988; Seiders and Cox, 1992; Dickinson, 1995). This is consistent with the fact that
the Juncal Formation of the Pine Mountain block sits depositionally upon crystalline basement
rocks (with ties to both the southeastern Salinian block and San Gabriel Mountain), whereas
Juncal assemblage rocks of the Sierra Madre Mountains are part of a more complete depositional
sequence extending into the Maastrichtian.
Seiders and Cox (1992) considered the Juncal Formation of the Pine Mountain block to
22
be early to middle Eocene in age. However, we assume an early Eocene age based on Jestes
(1963), Chipping (1972), and Dickinson (1995).
LV2
Juncal Formation. Unit Tjsh of Dibblee (2006d). Between localities LV-505 and LV-506 of
Seiders and Cox (1992). Lower Eocene.
LV3
Juncal Formation. Unit Tjsh of Dibblee (2006d). Between localities LV-506 and LV-507 of
Seiders and Cox (1992). Lower Eocene.
Point Lobos
We sampled the Carmelo Formation, which is interpreted as the fill of the upper reaches
of a submarine canyon incised into Salinian basement (porphyritic granodiorite of Monterey)
(Bowen, 1965; Clifton, 1981; Clifton and Hill, 1987; Cronin and Kidd, 1998). The Carmelo
Formation was initially considered to be Paleocene to earliest Eocene in age (Bowen, 1965;
Clark et al., 1984; Clifton and Hill, 1987; Bachman and Abbott, 1988; Seiders and Cox, 1992).
This suggested a broad correlation with a similar incised submarine canyon sequence of
Paleocene age in the Indians Ranch area (Anderson et al., 2006). However, recent unpublished
studies of foraminifera by Kristin McDougall cited by Clark (1997) and Dickinson et al. (2005)
indicate an early Eocene age (Penutian) for the Carmelo (confirmed by J. C. Clark, personal
communication, 2009). Nonetheless, we still consider that the Carmelo is more closely related to
the Merle Formation than to the middle Eocene Reliz Canyon and Church Creek Formations of
the Indians Ranch area. We thus plotted the zircon results for the Carmelo Formation along with
those for the Merle Formation in the mid Maastrichtian-Paleocene sample group, despite the
23
apparent early Eocene age of the former.
03-04
Carmelo Formation. Unit Tc of Dibblee (1999). Probably lower Eocene.
MO1
Carmelo Formation. Unit Tc of Dibblee (1999). Probably lower Eocene.
Point San Pedro
Paleocene (Ynezian) strata at Point San Pedro comprise a small, bathyal submarine fan
complex deposited on granodiorite of the Salinian block at Montara Mountain (Morgan, 1981;
Nilsen and Yount, 1981a, 1981b, 1987). The unit is dominated by fine-grained, thin-bedded
turbidites that are inferred to have been deposited in a channel-margin or interchannel setting.
Lesser conglomerate and coarse sandstone are interpreted as inner- and middle-fan channel
deposits, respectively. Morgan (1981) observed differences in the petrology of sandstones from
the turbiditic and channelized units. We obtained a total of 62 detrital zircon ages for four
samples from this area, three from turbidite units and one from a channel deposit. The number of
analyses is too small to provide a rigorous test, but, we see no striking difference in zircon
populations between the channelized and turbiditic units.
Champion et al. (1984) inferred from paleomagnetic data that the sedimentary rocks of
Point San Pedro were deposited approximately 2,000 km south of their present location. This
conflicts, however, with both geologic (Ross, 1984; Silver and Mattinson, 1986) and other
paleomagnetic data (Whidden et al., 1998) suggesting that the Salinian block is in place other
than for Neogene offset along the San Andreas system.
24
MM1, MM1A
Unnamed strata of Point San Pedro. Locality 2 of Nilsen and Yount (1981b, 1987). At this stop,
a conglomeratic unit sits above thin-bedded turbidites along an erosive contact. Sample MM1 is
a fine-grained sandstone from the lower unit. MM1A is a coarse-grained pebbly sandstone from
the upper conglomeratic unit. Paleocene.
MM2
Unnamed strata of Point San Pedro. Locality 3 of Nilsen and Yount (1981b, 1987). This is an
area of interbedded siliciclastic and carbonate turbidites. Sample MM2 is dominantly
siliciclastic, but includes 7% detrital carbonate grains. Paleocene.
MM3
Unnamed strata of Point San Pedro. Near locality 1 of Nilsen and Yount (1981b, 1987). This site
exposes thinly interbedded fine-grained sandstone, siltstone, and shale inferred to have been
deposited in an interchannel environment. Sample MM3 is from the fine-grained sandstone.
Paleocene.
Point Sur
The region around Point Sur exposes Upper Cretaceous sedimentary rocks both west and
east of the San Gregorio-Hosgri fault system (referred to as the Sur fault zone in this area;
Howell et al., 1977; Hall, 1991; Dickinson et al., 2005). The rocks west of the fault belong to the
Nacimiento block and are described herein. Those east of the fault lie within the Salinian block
and are described in the section on the northwest Santa Lucia Range.
Gilbert (1971) mapped all pre-Cenozoic rocks in the Point Sur area west of the San
Gregorio-Hosgri fault as part of the Franciscan Complex. Underwood (1977), however,
25
concluded that relatively well-bedded sandstones in the vicinity of Pfeiffer Beach, which he
referred to as the “Pfeiffer Beach slab,” comprised a separate unit from the Franciscan Complex.
This inference was based on the low grade of metamorphism (zeolite facies) and abundance of
detrital K-feldspar. These characteristics led Underwood (1977) to view the Pfeiffer Beach slab
as a trench-slope–basin deposit, analogous to interpretations for the Cambria and Point San Luis
slabs located 100 to 150 km south of Point Sur on the east side of the San Gregorio-Hosgri fault
(Howell et al., 1977; see also the section on the Cambria area). Hall (1991), on the other hand,
considered the Pfeiffer Beach slab of Underwood (1977) to be part of the Franciscan Complex,
but postulated a trench-slope origin for other well-bedded sandstones in the region. These were
assigned to the “Pfeiffer slab,” named for exposures along the north end of Pfeiffer Ridge. The
Pfeiffer slab of Hall (1991) is included in his “Upper Cretaceous western facies,” a general term
applied to Upper Cretaceous units of the Nacimiento block that are not part of the Franciscan
Complex.
Recent analyses of vitrinite reflectance and illite crystallinity suggest that both the
Pfeiffer Beach and Point San Luis slabs attained peak temperatures up to 200 °C, which seems
higher than expected for the setting of a trench-slope basin (Underwood et al., 1995; Underwood
and Laughland, 2001). These determinations have led Underwood et al. (1995) and Underwood
and Laughland (2001) to conclude that the Pfeiffer Beach and Point San Luis slabs units are part
of the Franciscan Complex, as was originally proposed for these rocks. Maximum temperatures
for the Cambria slab are not quite so high, which means that a trench-slope origin for this unit
remains plausible (Underwood and Howell, 1987). The Point Sur, Cambria, and Point San Luis
sequences all exhibit similar sandstone petrology (Lee-Wong and Howell, 1977; Dickinson et al.,
2005). Hence, irrespective of whether these units represent deposits of the trench or trench-slope,
26
it is reasonable to view them as related sands carried past the outer margin of the forearc basin.
In this sense, they are all potential analogs to the protolith of the Pelona-Orocopia-Rand schists.
The age of the well-bedded sandstones of the Point Sur area is not well constrained.
Gilbert (1973) noted that P/F and V/L values of these rocks are similar to those of the
Cenomanian to Coniacian part of the Great Valley Group. In contrast, Q-F-L values best match
those of the Santonian to Campanian part of the Great Valley. Our two youngest detrital zircon
ages from these rocks (Pfeiffer slab of Hall, 1991) are 84.5 ± 1.1 and 87.0 ± 1.5 Ma, with seven
ages in the range of 95.2–90.6 Ma. Consequently, these units are almost certainly Coniacian or
younger and perhaps no older than Campanian.
The location of the Point Sur area prior to Neogene strike-slip faulting is not clear. Hall
(1991) restored this region to a position opposite the Cambria slab of the San Simeon area,
whereas Dickinson et al. (2005) chose a location approximately 45 km farther southeast,
outboard of the Point San Luis slab (we utilize this restoration). In contrast, Underwood and
Laughland (2001) considered that the Franciscan and related rocks of the Point Sur region
underwent no more than 10-15 km of right-lateral slip along the San Gregorio-Hosgri fault.
BS1, BS1A
Pfeiffer slab of Hall (1991). Coniacian(?) to Campanian.
These two sandstones were selected for their differing compositional and textural
characteristics. Both include subequal proportions of quartz, feldspar, and lithics. Sample BS1
exhibits a higher P/K ratio (3.2 vs. 1.5) and shows significantly better sorting. We obtained 13
zircon ages from BS1 and 16 from BS1A. Based on this limited sampling, there is no obvious
difference in provenance despite the different sedimentologic characteristics.
27
PS2
Pfeiffer slab of Hall (1991). Coniacian to Campanian.
San Gabriel Block
The term “San Gabriel block” is used here to designate the region between the San
Gabriel and San Andreas faults. It includes the San Gabriel Mountains in the southeast and the
Soledad and Ridge Basins, Sierra Pelona, and Warm Springs and Liebre Mountain areas in the
northwest. A thickness of ~4 km of upper Maastrichtian-Paleocene sediments assigned to the San
Francisquito Formation crops out in the area of Warm Springs Mountain in depositional contact
with crystalline basement (Dibblee, 1967; Kooser, 1982). These strata include a basal nonmarine
to shallow-marine transgressive sequence overlain by two fining-upward submarine fan
sequences. The basal unit is time transgressive, ranging from late Maastrichtian to late early
Paleocene in age (Saul, 1983). The uppermost exposed part of the section is middle Paleocene in
age. The formation appears to show continuous deposition across the Cretaceous-Paleogene
boundary (Saul, 1983). The San Francisquito Formation is probably correlative with
Maastrichtian-Paleocene sections in the La Panza Range and southern Santa Lucia Range around
Santa Margarita Lake and Lake Nacimiento (Saul, 1983, 1986; Grove, 1993; Dickinson, 1995).
Approximately 1200 m of marine conglomerate, sandstone, and shale assigned by
Dibblee (1967) to the San Francisquito Formation crops in the vicinity of Valyermo in the
southeastern part of the San Gabriel block. These strata sit in depositional contact upon
granodiorite. They are middle to late Paleocene in age and thus mostly or entirely younger than
the San Francisquito Formation of the Warm Spring Mountains area (Kooser, 1982; Saul, 1983;
Squires, 1997).
28
SF1
San Francisquito Formation (Warm Springs Mountain section). Unit KTsa of Kooser (1982);
unit KTSfa of Dibblee (1997). This sample is from very close to the base of the unit on the long
ridge trending northeast from Warm Springs Mountains. Well-constrained upper Maastrichtian
fossil assemblages have been obtained from this area (Saul, 1983).
SF2
San Francisquito Formation (Warm Springs Mountain section). Unit KTsb of Kooser (1982);
unit Tsfc of Dibblee (1997). Maastrichtian or Paleocene.
SF4
San Francisquito Formation (Warm Springs Mountain section). Unit Tsf of Kooser (1982). Near
locality GV-469 of Seiders and Cox (1992). Grades to the west along strike into unit Tse. Lower
or middle Paleocene.
SF5
San Francisquito Formation (Warm Springs Mountain section). Unit Tse (or perhaps Tsf) of
Kooser (1982). Near locality GV-468 of Seiders and Cox (1992). Unit Tse forms a tongue within
unit Tsf. This locality sits stratigraphically above unit Tsf sampled at locality SF4. Lower or
middle Paleocene.
VA1
San Francisquito Formation (Valyermo section). Unit Tsfs of Dibblee (2002). Middle or upper
Paleocene.
San Rafael Mountains
The San Rafael Mountains extend from Cuyama Gorge, east of Santa Maria, in the
29
northwest to Wheeler Gorge, north of Ojai, in the southeast. They are separated from the Sierra
Madre Mountains to the northeast by the Nacimiento fault and from the Santa Ynez Mountains
to the south by the Santa Ynez fault. This region includes one of the most complete sections of
the forearc basin of any of the areas investigated in this study. We analyzed five Upper
Cretaceous samples and one Eocene sample from this area (however, for purposes of plotting, we
included the one Eocene sample with the Eocene samples from the Santa Ynez Range).
Upper Cretaceous rocks in the San Rafael Mountains are continuous at their base with
Upper Jurassic to Lower Cretaceous units that in turn sit depositionally upon the Coast Range
ophiolite (Dibblee, 1966; Hall and Corbató, 1967; MacKinnon, 1978; Vedder et al., 1983, 1998;
Dickinson, 1995). The above sequence is underlain structurally by the Franciscan Complex,
indicating that the San Rafael Mountains exhibit geologic affinities with the Nacimiento block.
In the southern San Rafael Mountains, the Upper Cretaceous sequence is overlain
unconformably to paraconformably by Paleogene strata. In most areas, the gap between the two
sequences spans most of the Maastrichtian and Paleocene. Elsewhere, condensed sections
indicate continuous, but slow, deposition across the Cretaceous-Paleogene boundary (Vedder et
al., 1998).
The Upper Jurassic to Upper Cretaceous sequence has an aggregate stratigraphic
thickness of 8000 m or greater and is composed mostly of turbidite. The lower part of the
sequence is dominated by shale and siltstone. The upper part includes a mix of shale, siltstone,
and sandstone. The lower part of the sequence has typically been referred to as the Jollo
Formation in the north (Hall and Corbató, 1967) and as the Espada Formation in the south
(Dibblee, 1966, 1991; Vedder et al., 1967, 1983; MacKinnon, 1978). Usage has varied, however,
regarding the location of the top of the Espada. Dibblee (1966) and MacKinnon (1978) included
30
units of early Late Cretaceous age in the Espada, whereas Dibblee (1991) and Vedder et al.
(1967, 1983) put the contact at the boundary between the Lower and Upper Cretaceous. Dibblee
(1966) originally divided the section above the Espada Formation into a lower unnamed shale
and upper unnamed sandstone. More recently, he reassigned the unnamed shale and sandstone
and the upper part of his original Espada Formation to the Cachuma Formation (Dibblee, 1991).
Note, however, that Vedder and Stanley (2001) raised several problems with the use of Cachuma
Formation as a formal stratigraphic term.
Upper Paleocene to Eocene sedimentary units in the southern San Rafael Mountains
range up to ~4,000 m in thickness and were deposited in basinal, nearshore, and fluvial
environments. The base of the section is defined by thin (typically 5-15 m), discontinuous lenses
of Paleocene Sierra Blanca Limestone (Vedder et al., 1983; Dickinson et al., 1995; Whidden et
al., 1995). The Sierra Blanca Limestone, where present, is overlain by the lower Eocene Juncal
Formation, which otherwise sits directly on the Cretaceous section (Thompson, 1988; Dickinson,
1995). The Juncal Formation consists largely of slope, fan, and basin plain deposits and is
overlain by a progradational, retrogradational, progradational sequence represented by Matilija
Sandstone, Cozy Dell Shale, and Coldwater Sandstone, respectively (Dibblee, 1966; Vedder et
al., 1983; Thompson, 1988). The Sierra Blanca to Coldwater section of the San Rafael
Mountains can be correlated closely with Paleogene strata of the Santa Ynez Mountains
(Dibblee, 1950, 1966; Link and Dibblee, 1988; Dickinson, 1995). For this reason, we have
plotted our single sample of Eocene age from the southern San Rafael Mountains (LP3, Juncal
Formation) along with our four Juncal to Matilija samples from the Santa Ynez Mountains. The
Eocene section from the southern San Rafael Mountains and Santa Ynez Mountains is
transitional with Eocene strata of the Sierra Madre Mountains (below; Chipping, 1972; Vedder et
31
al., 1983; Dickinson, 1995). These combined Eocene rocks appear to represent an overlap
assemblage postdating the suturing of the Nacimiento and Salinian blocks.
LP1
Unnamed sandstone of Dibblee (1966)/Cachuma Formation of Dibblee (1991). Unit Kss of
Dibblee (1986a). Aqua Caliente Canyon near debris dam. Upper part of Upper Cretaceous
section. Campanian (MacKinnon, 1978).
LP3
Juncal Formation. Unit Tjss of Dibblee (1986a). Aqua Caliente Canyon north of Pendola Guard
Station. Near base of Paleogene section. Early to middle Eocene (Dibblee, 1986a; Thompson,
1988; Vedder et al., 1998). This sample was plotted along with Eocene samples from the Santa
Ynez Mountains (see description of those rocks in the section on the Santa Ynez Mountains).
LP9
Unnamed shale or sandstone of Dibblee (1966; locality is off the edge of the mapped
area)/Cachuma Formation of Dibblee (1991). Unit Kss of Vedder et al. (1967); Unit Kcss of the
Cachuma Formation of Dibblee (2005). Sample is from the lowermost continuous sandstone bed
north of Manzana Creek shown on both Vedder et al. (1967) and Dibblee (2005). Age in this part
of the section is not well constrained (Vedder et al., 1998). A Campanian age seems most likely,
but a somewhat older age cannot be ruled out.
LP10
Unnamed sandstone of Dibblee (1966)/Cachuma Formation of Dibblee (1991). Unit Ks of
Vedder et al. (1967); unit Kcsh of the Cachuma Formation of Dibblee (1991, 2005). Manzana
Creek ~1 km southeast of Nira Campground. Sandstone bed from the mudstone-rich lower part
of the Upper Cretaceous section. Age is inferred to be Cenomanian-Turonian based on the
32
position of this locality along strike and stratigraphically slightly above beds of that age at Nira
Campground (see sample LP11).
LP11
Unnamed conglomerate of Dibblee (1966)/Cachuma Formation of Dibblee (1991). Unit Kc of
Vedder et al. (1967); Manzana Conglomerate Member (Kcgm) of Cachuma Formation of
Dibblee (1991, 2005). Manzana Creek near Nira Campground. Sandstone lens from within the
upper part of the conglomerate described by McLean et al. (1977). The conglomerate here
comprises the base of the Upper Cretaceous section. Cenomanian-Turonian (Vedder et al., 1967,
1998). The conglomerate includes significant felsic volcanic and plutonic clasts typical of
conglomerates from Cretaceous sedimentary units of this region (Seiders and Cox, 1992) and
which are likely derived from the Cretaceous Sierran-Salinian-Mojave arc. In addition, the
conglomerate locally contains abundant mafic clasts inferred to have been derived from the
Coast Range ophiolite, which forms the depositional base of the Jurassic-Cretaceous sequence.
TP1
Buckhorn sandstone of Crandall (1961)/Cachuma Formation of Dibblee (1991). Unit Kus of
Vedder et al. (1991); unit Kcss of Cachuma Formation of Dibblee (1991, 2005). Tepusquet
Canyon, south of Cuyama Gorge. Top of exposed Upper Cretaceous section. Campanian or
lower Maastrichtian (C.A. Hall, Jr., personal communication, 2001).
Santa Monica Mountains-Simi Hills
The Simi Hills and Santa Monica Mountains lie at the southeast corner of the western
Transverse Ranges transrotational province (Kamerling and Luyendyk, 1979, 1985; Luyendyk et
al., 1980, 1985; Luyendyk and Hornafius, 1987, Luyendyk, 1991; Dickinson, 1996; Prothero and
33
Vance, 1996; Prothero and Britt, 1998; Fritsche et al., 2001; Prothero, 2006). The two areas
expose similar Upper Cretaceous to Paleogene strata, although the section is more complete in
the Santa Monica Mountains (Carey and Colburn, 1978; Yerkes and Campbell, 1979, 2005;
Colburn et al., 1981; Bottjer and Link, 1984; Link et al., 1984; Fritsche et al., 2001). In the Santa
Monica Mountains, Cenomanian-Turonian sediments of the Trabuco Formation (up to 100 m
thick) sit unconformably above the Upper Jurassic Santa Monica Slate. The Trabuco Formation
is overlain by Upper Cretaceous beds (up to 800 m thick) originally referred to as the Chico
Formation, but named the Tuna Canyon Formation by Yerkes and Campbell (1979). The lower
part of the Tuna Canyon Formation is Turonian in age (Carey and Colburn, 1978; Saul and
Alderson, 2001; Shapiro et al., 2001). The upper part is middle(?) to late Campanian and
possibly early Maastrichtian in age (Carey and Colburn, 1978; Yerkes and Campbell, 1979,
2005; Popenoe et al., 1987; Shapiro et al., 2001). Carey and Colburn (1978) inferred a hiatus
between the Turonian and middle-upper Campanian parts of the formation, although Alderson
(1988) has argued that the upper part of the lower Tuna Canyon Formation includes beds of
Coniacian to Santonian age. The upper, Campanian-Maastrichtian(?) part of the formation,
which is the part we sampled, is inferred to have been deposited in a deep-water submarine fan
environment.
Upper Cretaceous strata in the Simi Hills (~1,800 m thick) were named the Chatsworth
Formation by Colburn et al. (1981). The depositional base is not exposed, nor has it been
encountered in the subsurface (Yerkes and Campbell, 2005). Sandstones from the Chatsworth
Formation are petrologically similar to those from the Tuna Canyon Formation and are inferred
to have been deposited in a similar deep-sea, submarine fan environment (Link et al., 1984). Age
ranges from late middle Campanian to early Maastrichtian, with the bulk of the formation being
34
late Campanian (Almgren, 1981; Colburn et al., 1981; Saul and Alderson, 1981; Saul, 1983;
Link et al., 1984; Popenoe et al., 1987; Elder and Saul, 1996; Stecheson, 2001; Squires and Saul,
2006).
Both the Chatsworth and Tuna Canyon Formations are overlain by Paleocene rocks along
a disconformity named the Runyon Canyon erosion surface by Colburn et al. (1988). The
disconformity reflects a gap in deposition that spans much of the Maastrichtian and early
Paleocene, and probably encompasses a somewhat greater time period in the Santa Monica
Mountains than the Simi Hills (Saul, 1983).
The Paleocene sections of the Simi Hills and Santa Monica Mountains are quite similar
(Nelson, 1925; Yerkes and Campbell, 1979, 2005; Parker, 1983; Colburn et al., 1988; Colburn
and Novack, 1989; Fritsche et al., 2001). The base of both sections is generally marked by the
Simi Conglomerate, which was deposited mostly under nonmarine conditions, probably as an
alluvial fan (Colburn and Novack, 1989). The upper part of the conglomerate, however, appears
to be at least partly of marine origin (Zinsmeister, 1975, 1983). A highly distinctive aspect of the
Simi Conglomerate is the presence of clasts of reddish quartz arenite, which Colburn and
Novack (1989) considered to have been derived from Precambrian or Cambrian units in the
Mojave Desert and/or Sonora Mexico. The formation also includes volcanic clasts which bear a
resemblance to the Poway clasts of the San Diego area (Woodford et al., 1968; Abbott and
Smith, 1978, 1989; Kies and Abbott, 1983). The Simi Conglomerate is sparsely fossiliferous but
locally contains early Paleocene mollusks (Evans and Miller, 1978). The top of the formation is
gradational into overlying units of late early to late Paleocene age.
Paleocene units above the Simi Conglomerate in the Simi Hills have been divided into
the Las Virgenes Sandstone and Santa Susana Formation (Nelson, 1925; Sage, 1975; Parker,
35
1983; Zinsmeister, 1983). In the Santa Monica Mountains, Paleocene strata above the Simi
Conglomerate were assigned to the Coal Canyon Formation by Yerkes and Campbell (1979).
Colburn et al. (1988), however, correlated these same beds with the Las Virgenes Sandstone and
Santa Susana Formation of the Simi Hills. We utilize the terminology of Colburn et al (1988).
The Las Virgenes Sandstone is composed largely of white, biotite-bearing arkose inferred
to have been deposited in a floodplain (Colburn and Novack, 1989) to nearshore or beach
environment (Zinsmeister, 1983). The unit is only sparsely fossiliferous, but appears to straddle
the boundary between the early and late Paleocene (Saul, 1983).
The Las Virgenes Sandstone is overlain by, and locally interfingers with, the shallow-
marine Santa Susana Formation (up to 1,000 m thick; Colburn et al., 1988; Colburn and Novack,
1989; Fritsche et al., 2001). The unit is mostly fine- to medium-grained, but locally
conglomeratic. It is commonly considered to be early late Paleocene to early Eocene or early
Eocene(?) in age (Yerkes and Campbell, 1979, 1995; Zinsmeister, 1983; Colburn et al., 1988;
Strathearn et al., 1988; Fritsche et al., 2001), although Squires and Saul (1998) note that
mollusks indicate a consistent late Paleocene age.
The Santa Susana Formation is overlain with slight disconformity by the Llajas
Formation (Evans and Miller, 1978; Squires, 1983; Fritsche et al., 2001; Yerkes and Campbell,
2005). The Llajas Formation is dominated by fine-grained sandstone and mudstone of shallow-
marine origin, but locally includes a nonmarine conglomerate at its base. In the Santa Monica
Mountains, clasts in the basal conglomerate of the Llajas Formation are similar in composition
and size to those within conglomerate layers of the underlying Santa Susana Formation (Fritsche
et al., 2001). The mudstones that comprise the bulk of the Llajas formation are also similar to
those within the Santa Susana Formation (Fritsche et al., 2001). These characteristics suggest
36
that the break in sedimentation between the Santa Susana and Llajas Formations does not mark a
significant event. The Llajas Formation is considered to be early to middle Eocene in age
(Squires, 1981, 1983; Yerkes and Campbell, 2005).
The Simi Hills and Santa Monica Mountains are commonly interpreted to have been
positioned at approximately the same latitude as, and outboard of (i.e., to the west of), the
northern Santa Ana Mountains prior to Neogene clockwise rotation and associated strike-slip
movement of the western Transverse Ranges province (Bottjer and Link, 1984; Link et al., 1984;
Alderson, 1988; Fritsche et al., 2001). Indeed, there are many similarities in the Cenomanian-
Turonian to Eocene sequences between the Simi Hills-Santa Monica Mountains and Santa Ana
Mountains. In detail, however, various contrasts in the stratigraphy and paleontology between
these areas suggest that water depths typically increased from east to west in reconstructed
coordinates during most of this time period (Fritsche et al., 2001; Saul and Alderson, 2001). In
addition, our zircon data suggest some differences in provenance between the two areas,
particularly during the late Campanian to early Maastrichtian.
SH1
Chatsworth Formation. Unit Kcs of Dibblee (1992a). Eastern Simi Hills. From approximately the
middle of the formation. Upper Campanian.
SH2
Simi Conglomerate. Unit Tsi of Dibblee (1992b). Northeastern margin of Simi Valley. Minor
sandstone lens within conglomerate. Ca. middle Paleocene.
SH6
Llajas Formation. Unit Tll of Dibblee and Ehrenspeck (1993a). Western Simi Hills. Lower part
of formation. Lower or middle Eocene.
37
SH7
Upper Chatsworth Formation. Unit Kcs of Dibblee and Ehrenspeck (1993a). Western Simi Hills.
Upper part of formation. Upper Campanian or lower Maastrichtian.
SH8
Santa Susana Formation. Unit Tsus of Dibblee and Ehrenspeck (1993a). Western Simi Hills.
Middle part of formation. Upper Paleocene.
SM2
Santa Susana Formation. Unit Tsu of Dibblee (1993). Equivalent to Stop 9 of Fritsche et al.
(2001). Rambla Pacifico Road, Santa Monica Mountains. Middle part of formation.
Conglomeratic member. Upper Paleocene.
SM3
Tuna Canyon Formation. Unit Kss of Dibblee and Ehrenspeck (1993b). Encompassed within
Stop 7 of Fritsche et al. (2001). Solstice Canyon, Santa Monica Mountains. Uppermost part of
formation. Upper Campanian or lower Maastrichtian.
SM4
Las Virgenes Sandstone. Included within the basal-most part of the Santa Susana Formation (unit
Tsu) of Dibblee and Ehrenspeck (1993b). Encompassed within Stop 7 of Fritsche et al. (2001).
Solstice Canyon, Santa Monica Mountains. Upper (middle upper?) Paleocene.
SM6, SM6A
Llajas Formation. Unit Tll of Dibblee and Ehrenspeck (1993b). Corral Canyon, Santa Monica
Mountains. Same locality as illustrated in Figure 22 of Fritsche et al. (2001). Lower part of
formation. Medium-grained sandstone (SM6) and siltstone (SM6A) collected to investigate
influence of grain size on detrital zircon age distribution (only 15 ages were determined per
38
sample, but the patterns are quite similar for the two). Lower or middle Eocene.
Santa Ynez Mountains
The Santa Ynez Mountains comprise an elongated, east-west–trending range along the
northern margin of the western Transverse Ranges. They merge to the east with the Topatopa
Mountains, the latter of which are located to the north of the Ventura Basin. The Santa Ynez and
Topatopa Mountains are together separated from the southeasternmost San Rafael Mountains to
the north by the east-west–trending, left-lateral Santa Ynez fault. The Santa Ynez and Topatopa
Mountains, as well as the part of the San Rafael Mountains south of the Big Pine fault, are
thought to have undergone ~90° of clockwise rotation since the middle Miocene (Kamerling and
Luyendyk, 1979, 1985; Luyendyk et al., 1980, 1985; Luyendyk and Hornafius, 1987, Luyendyk,
1991; Dickinson, 1996; Prothero and Vance, 1996; Prothero and Britt, 1998; Fritsche et al.,
2001; Prothero, 2006).
The Santa Ynez and Topatopa Mountains are underlain by an extensive Upper Jurassic to
Paleogene section broadly similar to that described above for the San Rafael Mountains
(Dibblee, 1950, 1966; Dickinson, 1995). Along most of the length of the combined Santa Ynez-
Topatopa Mountains, the section forms a relatively simple, south-dipping homocline, although
more complex folding occurs locally. Except in the westernmost Santa Ynez Mountains, which
we did not sample, rocks older than uppermost Cretaceous have been cut out along the Santa
Ynez fault. Our samples of this tectonostratigraphic block were collected in the Santa Ynez
Mountains north of Santa Barbara and in the Wheeler Gorge area north of Ojai, the latter of
which defines the boundary between the Santa Ynez Mountains and Topatopa Mountains.
Hence, we use the term “Santa Ynez Mountains” to refer to this group of samples, keeping in
39
mind that the geology is contiguous with that of the Topatopa Mountains.
As alluded to above, Upper Cretaceous rocks are not as widely exposed in the Santa
Ynez-Topatopa Mountains as they are north of the Santa Ynez fault, and correlation between
these two areas is uncertain. Dibblee (1950, 1966) assigned Upper Cretaceous rocks in the
westernmost Santa Ynez Mountains to the Jalama Formation. The type Jalama Formation was
originally considered to be upper Campanian or lower Maastrichtian (Dailey and Popenoe, 1966;
Almgren, 1973), but more recent studies suggest that it is entirely lower upper Campanian
(Squires and Saul, 2003). Rocks assigned to the Jalama(?) Formation crop out as several bands
between the Santa Ynez fault to the north and stratigraphically overlying Eocene beds to the
south (Dibblee, 1966, 1987; Rust, 1966). We analyzed one sample each from two such bodies,
one northeast of Santa Barbara along East Camino Cielo Road in the vicinity of Romero Saddle
and the other in the region of Wheeler Gorge. No fossils have been described from the section
near Romero Saddle (Dibblee, 1966), where correlation with the Jalama Formation is based
entirely on stratigraphic position and lithologic similarity. Our sample from this area was
analyzed toward the end of the study, when we began running samples using the LA-ICP-MS
technique. We obtained 72 detrital zircon ages from this sample. This includes two ages of 69
Ma and nine more ages in the range 75–71 Ma. It is thus unlikely that the depositional age of this
sample is any older than Maastrichtian. The section near Wheeler Gorge has yielded fossils
considered to be Late Campanian-Maastrichtian (Rust, 1966) or Campanian (Howell et al., 1977)
in age. The sample from this area was analyzed with the ion microprobe and we obtained only 29
ages (although this is still relatively high compared to the number of grains run for most other
samples analyzed using the ion microprobe). The youngest age from this sample is 74 Ma. Two
ages of 75 Ma and one of 76 Ma were also obtained. It is not known whether the difference in
40
youngest ages obtained from the two samples reflects true differences in depositional age,
analytical errors, or statistical issues related to the different number of grains analyzed. In any
case, at least the sample from near Romero Saddle appears somewhat younger than the type
Jalama of the westernmost Santa Ynez Mountains (Dibblee, 1950).
Dibblee (1966) suggested that the Jalama Formation might correlate with the Upper
Cretaceous rocks north of the Santa Ynez fault (see section on San Rafael Mountains). However,
our detrital zircon results show distinct differences between these two sections. Our samples of
Jalama(?) Formation contain significant numbers of zircons with a likely source in the central to
eastern Transverse Ranges and/or Mojave Desert (ages younger than 80 Ma and Proterozoic
ages). Such ages are sparse in the Upper Cretaceous section north of the Santa Ynez fault. It is
not possible with our limited number of samples and the uncertainty of biostratigraphic ages to
determine whether this is due to geographic position or to the Jalama(?) Formation being
somewhat younger than the Upper Cretaceous rocks north of the Santa Ynez fault.
The Santa Ynez Mountains include a thick sequence of mostly marine rocks of Paleogene
age (Dibblee, 1950, 1966; Vedder, 1972; Link and Welton, 1982; Vedder et al., 1983; Clark,
1994; Dickinson, 1995; Campion et al., 1996). North of the Santa Ynez fault, a discontinuous
algal limestone at the base of the sequence (Dibblee, 1966) may be as old as late Paleocene
(Sliter et al., 1994; Whidden et al., 1995; Vedder et al., 1998), but most of the section is early to
middle Eocene in age (Thompson, 1988; Clark, 1994; Squires, 1994; Dickinson, 1995; Campion
et al., 1996; Prothero and Vance, 1996; Prothero and Britt, 1998). The upper Paleocene-middle
Eocene sequence comprises part of a larger basinal assemblage that extends northward and
eastward into the southern San Rafael Mountains, Sierra Madre Mountains, and Pine Mountain
area (Dibblee, 1966, 1991; Chipping, 1972; Vedder et al., 1983; Thompson, 1988; Jiao and
41
Fritsche, 1994; Dickinson, 1995; Campion et al., 1996). In the inner parts of the basin (Pine
Mountain block, Sierra Madre Mountains), this section is depositional on crystalline rocks of the
Salinian-San Gabriel terrane or on older Paleocene to Maastrichtian marine units that are
themselves depositional on the same basement complex. In much of the central to outer parts of
the basin (southern San Rafael Mountains, Santa Ynez Mountains), the upper Paleocene-middle
Eocene sequence was deposited upon a package that includes the Coast Range ophiolite and
depositionally overlying Upper Jurassic through Upper Cretaceous forearc units analogous to
those of the Nacimiento block. As in the Nacimiento block, this forearc sequence is underlain
structurally by the Franciscan Complex. In most places within the Santa Ynez and southern San
Rafael Mountains, the upper Paleocene-middle Eocene units sit with relative conformity above
Upper Cretaceous beds. Locally, however, the contact cuts downsection, and in some areas
within the outermost part of the basin, the lower Paleogene section was deposited directly upon
Franciscan rocks (Dibblee, 1966; Dickinson, 1995). This indicates an uplifted forearc high
during the early Cenozoic (Dickinson, 1995). The upper Paleocene-middle Eocene section is
thickest within the center of the basin and thins both eastward (northward prior to middle to late
Cenozoic rotation) toward the inner margin and westward toward the uplifted Franciscan outer
margin (Dickinson, 1995). Within the Santa Ynez Mountains, the section is thickest (~4,000 m)
at the eastern boundary with the Topatopa Mountains.
The upper Paleocene-middle Eocene section represents a range of depositional
environments from deep marine to littoral and even nearshore subaerial. Overall, the sedimentary
sequence reflects a progressive infilling of the basin with time, culminating in the deposition of
the upper middle Eocene to Miocene nonmarine Sespe Formation (not analyzed here). Several
secondary transgressive-regressive sequences, however, can be recognized within the larger
42
shallowing-upward progression. In addition, within any given time period, deeper-water
sequences tend to occur toward the west (in present-day coordinates).
Within the Santa Ynez Mountains, the base of the upper Paleocene-middle Eocene
section is generally marked by the Juncal Formation, although in some localities the Juncal is
conformable above upper Paleocene Sierra Blanca Limestone. Abundant shales and thin-bedded
turbidites of the Juncal Formation represent basin plain, slope, fan, and lobe-fringe deposits
(Thompson, 1988; Dickinson, 1995). Thicker sand units are interpreted as outer-fan depositional
lobes and mid-fan channels. To the north and east of the Santa Ynez Mountains (e.g., Pine
Mountain Block), the Juncal Formation grades into coarser, inner-fan sequences. The Juncal
Formation appears to be largely early Eocene in age, but locally may be as old as late Paleocene
or as young as middle Eocene (Thompson, 1988; Sliter et al., 1994; Dickinson, 1995; Prothero,
2001). As is true for the lower to middle Eocene formations as a whole, age decreases to the west
(i.e., the individual formations are time transgressive).
The Juncal Formation of the Santa Ynez Mountains is overlain by the Matilija Sandstone
(Link, 1975; Link and Welton, 1982). The lower part of the Matilija consists mostly of a
shallowing-upward sequence of turbidite sandstones inferred to represent a deep-sea fan
complex. These beds are overlain by a shallow-marine sequence including abundant deposits of
inferred nearshore origin. Shallow-marine sandstones in the uppermost part of the formation are
part of a transgressive sequence that is transitional into the overlying Cozy Dell Shale. The lower
part of the Matilija Sandstone may be early Eocene in age, but much of the unit appears to be
middle Eocene (Clark, 1994; Prothero and Britt, 1998; Prothero, 2001).
Overlying and transitional with the Matilija Sandstone is the Cozy Dell Shale, which
represents a local transgressive phase within the overall regressive early to middle Eocene
43
sequence (Dibblee, 1966; Link and Welton, 1982; Dickinson, 1995; Squires, 1994; Campion et
al., 1996). The Cozy Dell Shale consists mostly of shale and siltstone, although thick sandstone
bodies are present locally. Depositional environments are inferred to have been largely outer
shelf and slope (Dickinson, 1995) or slope and basin plain (Squires, 1994). The age is middle
Eocene (Dibblee, 1966; Link and Welton, 1982; Squires, 1984; Dickinson, 1995; Prothero and
Britt, 1998).
The Cozy Dell Shale is overlain by the Coldwater Sandstone. The contact is gradational
in most places but disconformable in others (Dibblee, 1966; Vedder, 1972; Clark, 1994; Prothero
and Vance, 1996). Considerable disagreement exists as to the exact placement of the contact (see
discussion in Prothero and Vance, 1996, p. 157). The Coldwater Sandstone was deposited in a
mostly nearshore marine environment, but also includes various subaerial coastal facies
(Dibblee, 1966, Jiao and Fritsche, 1994; Dickinson, 1995). Redbeds are present locally. The
formation grades westward into the more basinal Sacate Formation (Dickinson, 1995). The age is
middle Eocene (Dibblee, 1966; Dickinson, 1995; Prothero and Vance, 1996). The Coldwater
Sandstone is gradational with the overlying, mostly nonmarine, Sespe Formation, although in
some areas there is a significant erosional discordance between the two units (Howard, 1989;
Jiao and Fritsche, 1994; Dickinson, 1995; Prothero et al., 1996).
As noted above, the upper Paleocene-middle Eocene section shows significant lateral
variations in lithology and depositional environment, generally reflecting a deepening from east
to west in present-day coordinates (Dickinson, 1995, Fig. 14). Notably, however, these variations
do not appear to correspond with the position of the Nacimiento fault or its presumed southern
continuation, the Pine Mountain fault. This suggests that the upper Paleocene-middle Eocene
units comprise an overlap assemblage postdating the juxtaposition of the Nacimiento and
44
Salinian blocks (but note that the sequence onlaps basement to the northeast and may not be
older than Eocene northeast of the Nacimiento fault).
LP3
Juncal Formation. See section on San Rafael Mountains. This sample is located north of the
Santa Ynez fault and thus belongs to the San Rafael Mountain region as defined above.
However, the Eocene stratigraphy at the locality of LP3 is very similar to that of the Santa Ynez
Range (Dibblee, 1966). In addition LP3 is our only Eocene sample from the San Rafael
Mountains, whereas we analyzed four Eocene samples from the Santa Ynez Mountains.
Particularly because we obtained only 15 analyses from Sample LP3, and the results were very
similar to those from the Eocene samples of the Santa Ynez Mountains, we have plotted LP3 and
the Eocene samples from the Santa Ynez Mountains as a single group.
LP7
Cozy Dell Shale. Unit Tcdss of Dibblee (1986b). Along Gibraltar Road north of Santa Barbara.
Sandstone unit within middle-lower part of formation. Middle Eocene.
LP12
Jalama(?) Formation. Unit Kucg of Dibblee (1985). Equivalent to locality WH-518 of Seiders
and Cox (1992). Wheeler Gorge. Coarse sandstone adjacent to the well-known conglomerate
(Rust, 1966; Walker, 1985; Dibblee, 1987; Link and Dibblee, 1988). Late Campanian-
Maastrichtian (Rust, 1966) or Campanian (Howell et al., 1977).
LP13
Coldwater Sandstone. Unit Tcw of Dibblee (1987). Near Stop 5 of Link and Dibblee (1988).
Ventura River valley north of Ojai. Various authors have mapped the base of the Coldwater
Sandstone in different positions (see discussion in Prothero and Vance, 1996, p. 157). Stop LP13
45
is in the middle of the formation according to Dibblee (1987), but near the base according to
Jestes (1963), Fritsche (1994), and Squires (1994). Middle Eocene.
LP14
Cozy Dell Shale. Unit Tcdss of Dibblee (1987). Equivalent to Stop 4 of Link and Dibblee
(1988). Ventura River valley north of Ojai. From thick sandstone unit in lower-middle part of the
formation (“mid-Cozy Dell sandstone”; Clark, 1994). Middle Eocene.
LP15
Matilija Sandstone. Unit Tma of Dibblee (1987). Near Stop 3 of Link and Dibblee (1988).
Ventura River valley north of Ojai. Middle Eocene.
LP21
Jalama(?) Formation. Unit Kj of Dibblee (1966); unit Kucg of Dibblee (1986c). East Camino
Cielo Road near Romero Saddle. Sandstone bed within dominantly conglomeratic unit. No
fossils reported from this area (Dibblee, 1966). Late Campanian or Maastrichtian based on
inferred correlation with fossiliferous sections of Jalama Formation elsewhere (Squires and Saul,
2003). No older than Maastrichtian based on our detrital zircon ages.
Sierra Madre Mountains
Unnamed Paleocene to Eocene rocks in the Sierra Madre Mountains define a section over
5,000 m in thickness continuous with Maastrichtian strata of the La Panza Range (Chipping,
1972; Vedder et al., 1983; Grove, 1989, 1993; Dickinson, 1995). Dickinson (1995) included
these rocks in his Juncal assemblage, which is considered to be late Paleocene to early Eocene in
age. Juncal assemblage rocks in the Sierra Madre Mountains comprise a sand-rich turbidite
sequence that probably formed in a mid-fan to locally inner-fan and slope environment
46
(Chipping, 1972; Dickinson, 1995). Chipping (1972) noted a strong similarity of the Sierra
Madre sequence to Eocene units in the Pine Mountain block and Orocopia Mountains. Facies in
the latter two areas, however, are generally more proximal than those of the Sierra Madre
Mountains. In contrast, more distal, shale-rich facies of the Juncal assemblage occur south of the
Big Pine and Pine Mountain faults and in the Santa Ynez Mountains.
MP1
Unnamed sandstone. Unit Tus of Vedder et al. (1989b); near boundary between interfingering
units Tss and Tssg of Dibblee (2006e). Equivalent to locality MP-525 of Seiders and Cox (1992).
Seiders and Cox (1992) consider this locality to be early Eocene in age.
MP2
Unnamed sandstone. Unit Tus of Vedder et al. (1989b); near boundary between interfingering
units Tss and Tssg of Dibblee (2006e). Equivalent to locality MP-526 of Seiders and Cox (1992).
Seiders and Cox consider this locality to be early Eocene in age.
MP3
Unnamed sandstone. Unit Tus of Vedder et al. (1989b); unit Tssg of Dibblee (2006e). Equivalent
to locality MP-528 of Seiders and Cox (1992). Seiders and Cox consider this locality to be
Paleocene or early Eocene in age. Sample MP3 comes from the same stratigraphic sequence as
Eocene samples MP1 and MP2 (above) and sample PZ4 from the La Panza area, which we have
included in the Paleocene age group. Stratigraphically, sample MP3 is located much closer to
samples MP1 and MP2 than to PZ4, so we include it in our Eocene group.
47
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72
DATA REPOSITORY FIGURE CAPTIONS
Figure DR1. Detrital zircon age distributions for the Catalina Schist of Santa Catalina Island and
the Rand Schist of the San Emigdio Mountains. Note break in scale of x-axis at 300 Ma.
Different vertical scales were also used for the left and right halves of the relative probability
plots. For most probability plots in the main text and Data Repository item, the vertical scales
were adjusted so that equal areas to the left and right of the break in the x-axis represent equal
probability. In this figure, however, ages >300 Ma include an additional vertical exaggeration by
a factor of two. Paired numbers in parentheses indicate number of samples and number of zircon
ages.
Figure DR2. Similar to Figure 6 of the main text. Dashed gray lines delineate four geographic
subregions (NW—northwest; NC—north-central; SC—south-central; SE—southeast) based on
along-strike variations in provenance that are particularly evident in Maastrichtian and younger
samples. Probability plots of zircon ages for the four subregions shown in this figure are
presented in Figures DR3 and DR4. Note that the subregions are subject to modification
depending on the age and nature of slip on the Nacimiento fault. Because movement was most
likely over by the late Paleocene, the Eocene reconstruction (D) would not be changed. All
preceding time frames, however, could be impacted to varying degrees. If the Nacimiento fault is
primarily a thrust fault (Page, 1970, 1981; Hall 1991; Saleeby, 2003), then any displacement
would have been in a direction approximately normal to the strike of the margin. In this case, the
northwest-southeast subdivisions should not require any significant modification. On the other
hand, a major component of sinistral displacement on the Nacimiento fault (Dickinson, 1983;
73
Dickinson et al., 2005) would necessitate a substantial revision in the paleogeography. However,
all localities within the northwest subarea except one (Pigeon Point) are located inboard of the
Nacimiento fault. Likewise, all localities within the south-central and southeast subareas lie
outboard of the inferred trace of the Nacimiento fault. Only the north-central area includes a
substantial proportion of sample sites both inboard and outboard of the Nacimiento fault. Thus,
even in the case of sinistral slip, the sample groupings defined here are for the most part
reasonable, even if the groups were positioned in alternate locations prior to faulting. Fault
abbreviations: EHf—East Huasna; Gf—Garlock; Nf—Nacimiento; Rf—Rinconada; SAf—San
Andreas; SGf—San Gabriel; SGHf—San Gregorio-Hosgri. Abbreviations for geologic ages:
Camp—Campanian; Cen—Cenomanian; Maast—Maastrichtian; Tur—Turonian.
Figure DR3. Detrital zircon age distributions for the forearc sedimentary units plotted according
to the northwest-southeast subareas areas defined in Figure DR2. The data are exactly the same
as those plotted in Figures 5F–5J of the main text, but here grouped according to geographic
location rather than depositional age. As discussed in the caption to Figure DR2, the subregions
are subject to modification depending on the age and nature of slip on the Nacimiento fault. See
Figure 5 of the main text and Figure DR1 for explanation of the scale break at 300 Ma. Paired
numbers in parentheses indicate number of samples and number of zircon ages.
Figure DR4. Detrital zircon age distributions for Eocene forearc sedimentary units plotted
according to the geographic areas defined in Figure DR2. Similar to Figure DR3, except that
units older than Eocene have been excluded because of possibility that they underwent
translation along the Nacimiento fault. See Figure 5 of the main text and Figure DR1 for
74
explanation of the scale break at 300 Ma. Paired numbers in parentheses indicate number of
samples and number of zircon ages.
Figure DR5. Ternary plot of total quartz (Qt), total feldspar (F), and nonquartzose lithic grains
(L) for the forearc sedimentary samples. Provenance fields after Dickinson (1985). Samples
analyzed in this study are plotted by age and area (filled squares). Age abbreviations: Eoc—early
to middle Eocene, Klu—Cenomanian-Turonian; KP—middle Maastrichtian-Paleocene; Kuu—
Campanian-early Maastrichtian. Location abbreviations based on subareas defined in main text:
NC—north-central; NW—northwest; SC—south-central; SE—southeast. Filled circles represent
basement uplift (B), dissected arc (D), transitional arc (T), and undissected arc (U) sample
groups of Ingersoll and Eastmond (2007). Filled triangles represent analyses of Great Valley
Group from Ingersoll (1983) as shown in Table 1 of the main text.
Figure DR6. Ternary plot of monocrystalline quartz (Qm), potassium feldspar (K), and
plagioclase feldspar (P) for the forearc sedimentary samples. Symbols and abbreviations as in
Figure DR5. Samples from Ingersoll (1983) are excluded because the published data are
insufficient for calculating QmKP values.
Figure DR7. Relative contents of total quartz (Qt), total feldspar (F), and nonquartzose lithic
grains (L) plotted using the geographic groupings and palinspastic base of Figure DR2. Numbers
in parentheses indicate number of samples studied petrographically.
Figure DR8. Relative contents of monocrystalline quartz (Qm), potassium feldspar (K), and
75
plagioclase feldspar (P) plotted using the geographic groupings and palinspastic base of Figure
DR2. Numbers in parentheses indicate number of samples studied petrographically.
Figure DR9. Relative contents of metamorphic (Lm), volcanic (Lv), and sedimentary (Ls) lithic
grains plotted using the geographic groupings and palinspastic base of Figure DR2. Numbers in
parentheses indicate number of samples studied petrographically.
Figure DR10. Detrital zircon age distributions for the Rand Schist and Cambria and Pfeiffer
slabs of the Nacimiento block. See Figure 5 of the main text and Figure DR1 for explanation of
the scale break at 300 Ma. Paired numbers in parentheses indicate number of samples and
number of zircon ages. Note the strong match between the Rand Schists and Cambria and
Pfeiffer slabs. The Cambria and Pfeiffer slabs are interpreted as either trench deposits or trench-
slope–basins tied to the Franciscan depositional system (Underwood and Howell, 1987; Hall,
1991; Underwood and Laughland, 2001; Dickinson et al., 2005). The above match supports a
close relationship between the POR-Catalina schists and Franciscan Complex.
REFERENCES CITED
Dickinson, W.R., 1985, Interpreting provenance relations from detrital modes of sandstones, in
Zuffa, G.G., ed., Provenance of Arenites: Boston, D. Reidel, p. 333–361.
Dickinson, W.R., Ducea, M., Rosenberg, L.I., Greene, H.G., Graham, S.A., Clark, J.C., Weber,
G.E., Kidder, S., Ernst, W.G., and Brabb, E.E., 2005, Net dextral slip, Neogene San
Gregorio–Hosgri fault zone, coastal California: Geologic evidence and tectonic implications:
Geological Society of America Special Paper 391, 43 p., doi: 10.1130/2005.2391.
76
Hall, C.A., Jr., 1991, Geology of the Point Sur-Lopez Point region, Coast Ranges, California; A
part of the Southern California Allochthon: Geological Society of America Special Paper
266, 40 p.
Ingersoll, R.V., 1983, Petrofacies and provenance of late Mesozoic forearc basin, northern and
central California: American Association of Petroleum Geologists Bulletin, v. 67, p. 1125–
1142.
Ingersoll, R.V., and Eastmond, D.J., 2007, Composition of modern sand from the Sierra Nevada,
California, U.S.A.: Implications for actualistic petrofacies of continental-margin magmatic
arcs: Journal of Sedimentary Research, v. 77, p. 784–796.
Underwood, M.B., and Howell, D.G., 1987, Thermal maturity of the Cambria slab, an inferred
trench-slope basin in central California: Geology, v. 15, p. 216–219, doi: 10.1130/0091-
7613(1987)15<216:TMOTCS>2.0.CO;2.
Underwood, M.B., and Laughland, M.B., 2001, Paleothermal structure of the Point San Luis slab
of central California: Effects of Late Cretaceous underplating, out-of-sequence thrusting, and
late Cenozoic dextral offset: Tectonics, v. 20, p. 97–111, doi: 10.1029/1999TC001153.
Catalina (21/305)
50 100 150 200 250 300
Detrital Zircon Age (Ma)
San Emigdio (3/82)
Rel
ativ
e Pr
obab
ility
BVert exag = 2for ages>300 Ma
600 900 1200 1500 1800 2100
Vert exag = 2for ages>300 Ma
C
0
20
40
60
80
10050 100 150 200 250 300
C
umul
ativ
e Pr
ob.
600 900 1200 1500 1800 2100
A
Catalina San Emigdio
Northwest (NW) (17/283)
North-Central (NC) (33/509)
South-Central (SC) (26/654)
50 100 150 200 250 300
Detrital Zircon Age (Ma)
Southeast (SE) (24/1149)
B
C
D
600 900 1200 1500 1800 2100
E
0
20
40
60
80
10050 100 150 200 250 300
Forearc Sedimentary Units
NWSE
NC
SC
600 900 1200 1500 1800 2100
A
Cum
ulat
ive
Prob
. R
elat
ive
Prob
abili
ty
NW (3/78)
Rel
ativ
e Pr
obab
ility
NC (7/99)
SC (10/239)
50 100 150 200 250 300
Detrital Zircon Age (Ma)
SE (8/411)
B
C
D
600 900 1200 1500 1800 2100
E
0
20
40
60
80
10050 100 150 200 250 300
C
umul
ativ
e Pr
ob.
SENW
NC
SC
600 900 1200 1500 1800 2100
A
Eocene Forearc Units
0.00 0.25 0.50 0.75 1.00
0.00
0.25
0.50
0.75
1.000.00
0.25
0.50
0.75
1.00
B D
T
U
Stony Creek
Grabast
Rumsey
SC KuuSC KP
SC Eoc
NC Klu
NC Kuu
NW KP
NC Eoc
NW KuuNC KP
NW Eoc
LF
Qt
UndissectedMagmatic Arc
TransitionalMagmatic Arc
DissectedMagmatic Arc
RecycledOrogenic
CratonInterior
TransitionalContinental
BasementUplift
0.00 0.25 0.50 0.75 1.00
0.00
0.25
0.50
0.75
1.000.00
0.25
0.50
0.75
1.00
T
D
U
BSC Kuu
SC KP
SC Eoc NC Klu
NC Kuu
NW KP
NC Eoc
NW Kuu
NC KPNW Eoc
PK
Qm
Rel
ativ
e Pr
obab
ility Cambria/Pfeiffer Slabs (6/107)
50 100 150 200 250 300
Detrital Zircon Age (Ma)
Rand Schist (11/341)
B
600 900 1200 1500 1800 2100
C
0
20
40
60
80
10050 100 150 200 250 300
C
umul
ativ
e Pr
ob.
600 900 1200 1500 1800 2100
A
Cambria/Pfeiffer Slabs Rand Schist
TABLE DR1. SAMPLES OF POR-CATALINA SCHIST ANALYZED FOR DETRITAL ZIRCON AGES
Sample Area* Group† Quad§ UTM (NAD27)
Zone Easting Northing
98-237 East Fork Pelona Mount San Antonio 11 431641 3802224 98-240 Blue Ridge Pelona Mount San Antonio 11 431487 3803663 98-241 Sierra Pelona Pelona Green Valley 11 367703 3821369 99-57 San Emigdio Mts. Cat-San Emig Cuddy Valley 11 307173 3860678 02-342 Sierra de Salinas Rand Palo Escrito Peak 10 640964 4028026 02-345 Sierra de Salinas Rand Palo Escrito Peak 10 640833 4027773 02-358 Sierra de Salinas Rand Palo Escrito Peak 10 637827 4030154 04-SE1B San Emigdio Mts. Cat-San Emig Pleito Hills 11 310653 3861786 BR218 Blue Ridge Pelona Mount San Antonio 11 434454 3803627 CD7 Castle Dome Mts. Pelona Castle Dome Peak 11 765922 3658934 CD9 Castle Dome Mts. Pelona Castle Dome Peak 11 765636 3659319 DR-1656 Sierra de Salinas Rand 10 JM-80-102 Sierra de Salinas Rand 10 KE12702 Orocopia Mts. Orocopia Red Canyon 11 617253 3712830 KE22431 Orocopia Mts. Orocopia Orocopia Canyon 11 614684 3708983 KE24033 Orocopia Mts. Orocopia Red Canyon 11 618865 3711985 KE4 Castle Dome Mts. Orocopia Slumgullion Pass 11 776537 3656621 KE6 Castle Dome Mts. Orocopia Slumgullion Pass 11 775745 3655262 MW10 Trigo Mts. Orocopia Picacho 11 725790 3654909 NR1 Neversweat Ridge Orocopia Neversweat Ridge 12 240274 3662994 NR2 Neversweat Ridge Orocopia Neversweat Ridge 12 240443 3663413 OR15A Orocopia Mts. Orocopia Orocopia Canyon 11 605971 3717226 OR113 Orocopia Mts. Orocopia Orocopia Canyon 11 610846 3713131 OR307 Orocopia Mts. Orocopia Orocopia Canyon 11 610924 3717529 OR312A Orocopia Mts. Orocopia Orocopia Canyon 11 610099 3716481 OR314 Orocopia Mts. Orocopia Orocopia Canyon 11 609938 3716171 OR337 Orocopia Mts. Orocopia Mortmar 11 600624 3720286 OR77B Orocopia Mts. Orocopia Orocopia Canyon 11 613409 3714761 PK114B SE Chocolate Mts. Orocopia Quartz Peak 11 703878 3659663 PM1 Mount Pinos Pelona Sawmill Mt. 11 303660 3856507 PM3 Mount Pinos Pelona Sawmill Mt. 11 302702 3857302 PM4 Mount Pinos Pelona Sawmill Mt. 11 302526 3858447 PM9 Mount Pinos Pelona Sawmill Mt. 11 297063 3858531 PM11 Mount Pinos Pelona Sawmill Mt. 11 297746 3858923 PR150 Portal Ridge Rand Ritter Ridge 11 386955 3830870 RA58 Rand Mts. Rand Johannesburg 11 436009 3910562 RA89 Rand Mts. Rand Johannesburg 11 434922 3908890 RA169 Rand Mts. Rand Johannesburg 11 435621 3912289 RA170 Rand Mts. Rand Saltdale SE 11 431438 3909618 RA175 Rand Mts. Rand Johannesburg 11 441022 3913238 SE03 San Emigdio Mts. Cat-San Emig Pleito Hills 11 SG532 East Fork Pelona Mount San Antonio 11 433398 3800745 SG533 East Fork Pelona Telegraph Peak 11 444292 3795208 SG69 East Fork Pelona Mount San Antonio 11 431551 3793948 SP10 Sierra Pelona Pelona Green Valley 11 369567 3822959 SP25D Sierra Pelona Pelona Green Valley 11 371584 3825297 SP60 Sierra Pelona Pelona Ritter Ridge 11 389118 3822125 SP70 Sierra Pelona Pelona Ritter Ridge 11 389815 3824434 SP71 Sierra Pelona Pelona Sleepy Valley 11 375513 3825727 SP81 Sierra Pelona Pelona Green Valley 11 367090 3819953 TR23 Trigo Mts. Orocopia Picacho 11 726889 3658508 TR24A Trigo Mts. Orocopia Picacho 11 729928 3659929 UG1417A SE Chocolate Mts. Orocopia Picacho Peak 11 710524 3653248 UG1500 SE Chocolate Mts. Orocopia Picacho Peak 11 712678 3653280 YN17 Trigo Mts. Orocopia Picacho SW 11 720800 3653598
*Geographic area as defined in Figure 1 of the main text. †Geographic group as defined in Figures 3 and 4 of the main text. §U.S. Geological Survey 7.5’ topographic quadrangle map.
TABLE DR2. SAMPLES OF FOREARC SEDIMENTARY UNITS ANALYZED FOR DETRITAL ZIRCON AGES
Sample Unit Area* Group† Age§ Quad# UTM (NAD27)
Zone Easting Northing
03-01 Cambria slab CA NC Kuu Cayucos 10 682120 3927897 03-03 Cambria slab CA NC Kuu Cambria 10 672991 3934523 03-04 Carmelo Fm PL NW Eoc** Monterey 10 595908 4042277 99-65 Rumsey DP N/A†† Kuu Patterson 10 655929 4148737 99-66A Cambria slab CA NC Kuu Cambria 10 670306 3939036 99-68 Atascadero Fm AT NC Kuu Atascadero 10 709647 3925864 BB1 Butano Ss BL NW Eoc Big Basin 10 572039 4110807 BS1 Pfeiffer slab PS NC Kuu Big Sur 10 603310 4015020 BS1A Pfeiffer slab PS NC Kuu Big Sur 10 603310 4015020 ES1 Unnamed SL NW KP Lopez Point 10 623034 3998219 IR1 Unnamed IR NW KP Cone Peak 10 635667 3996866 IR3 Reliz Canyon or
Church Creek Fm IR NW Eoc Cone Peak 10 637866 3998306
IR4 Church Creek Fm IR NW Eoc Cone Peak 10 638692 3997027 IR5 Merle Fm IR NW KP Cone Peak 10 644005 3994242 LP1 Unnamed SR SC Kuu Hildreth Peak 11 264971 3825014 LP3 Juncal Fm SY§§ SC Eoc Hildreth Peak 11 263633 3821856 LP7 Cozy Dell Sh SY SC Eoc Santa Barbara 11 253840 3817806 LP9 Unnamed SR SC Kuu Bald Mtn 11 233724 3851341 LP10 Unnamed SR SC Klu Bald Mtn 11 232065 3850814 LP11 Unnamed SR SC Klu Bald Mtn 11 231078 3851348 LP12 Jalama Fm? SY SC Kuu Wheeler Springs 11 291184 3820606 LP13 Coldwater Ss SY SC Eoc Matilija 11 289771 3816942 LP14 Cozy Dell Sh SY SC Eoc Matilija 11 289198 3817990 LP15 Matilija Ss SY SC Eoc Matilija 11 288455 3818355 LP21 Jalama Fm SY SC Kuu Carpinteria 11 262670 3818236 LV2 Juncal Fm PM NC Eoc Lockwood Valley 11 309795 3835412 LV3 Juncal Fm PM NC Eoc Lockwood Valley 11 309273 3835069 MM1 Unnamed PSP NW KP Montara Mountain 10 543515 4159755 MM1A Unnamed PSP NW KP Montara Mountain 10 543515 4159755 MM2 Unnamed PSP NW KP Montara Mountain 10 542895 4159525 MM3 Unnamed PSP NW KP Montara Mountain 10 543400 4160970 MO1 Carmelo Fm PL NW Eoc** Monterey 10 594197 4041486 MP1 Unnamed SMM NC Eoc Miranda Pine Mtn 10 770593 3880574 MP2 Unnamed SMM NC Eoc Miranda Pine Mtn 10 768593 3884433 MP3 Unnamed SMM NC Eoc Miranda Pine Mtn 10 766615 3887267 OR432 Maniobra Fm OR NC Eoc Red Canyon 11 620995 3718770 OR433 Maniobra Fm OR NC Eoc Red Canyon 11 621051 3719525 PP1 Pigeon Point Fm PP NW Kuu Pigeon Point 10 553692 4115351 PP2 Pigeon Point Fm PP NW Kuu Pigeon Point 10 551850 4121206 PP3 Pigeon Point Fm PP NW Kuu San Gregorio 10 552011 4123408 PS1 Unnamed SL NW KP Point Sur 10 598978 4023213 PS2 Pfeiffer slab PS NC Kuu Point Sur 10 599439 4020054 PT1 Unnamed SL NW KP Partington Ridge 10 620952 4000644 PZ1 Unnamed LP NC KP Pozo Summit 10 744929 3913688 PZ3 Unnamed LP NC KP Pozo Summit 10 744324 3911924 PZ4 Unnamed LP NC KP Pozo Summit 10 746684 3905207 SF1 San Francisquito Fm SG NC KP Warm Springs Mt 11 355562 3829558 SF2 San Francisquito Fm SG NC KP Warm Springs Mt 11 354911 3829381 SF3 “San Francisquito Fm” CP NC KP Cajon 11 458592 3792440 SF4 San Francisquito Fm SG NC KP Green Valley 11 366532 3827733 SF5 San Francisquito Fm SG NC KP Green Valley 11 366195 3826993 SH1 Chatsworth Fm SM SC Kuu Calabasas 11 346140 3789640 SH2 Simi Cgl SM SC KP Santa Susana 11 346186 3794292 SH6 Llajas Fm SM SC Eoc Thousand Oaks 11 334263 3788564 SH7 Chatsworth Fm SM SC Kuu Thousand Oaks 11 333654 3786884 SH8 Santa Susana Fm SM SC KP Thousand Oaks 11 333495 3787995 SM2 Santa Susana Fm SM SC KP Malibu Beach 11 347618 3769482 SM3 Tuna Canyon Fm SM SC Kuu Point Dume 11 337515 3770706 SM4 Las Virgenes Ss SM SC KP Point Dume 11 337604 3770788 SM6 Llajas Fm SM SC Eoc Point Dume 11 338207 3771116 SM6A Llajas Fm SM SC Eoc Point Dume 11 338207 3771116 SM8 Tuna Canyon Fm SM SC Kuu Malibu Beach 11 348758 3769919 SML1 Unnamed LP NC KP Lopez Mountain 10 726164 3914732 TP1 Buckhorn Ss SR SC Kuu Tepusquet Cyn 10 755891 3875101 VA1 San Francisquito Fm SG NC KP Valyermo 11 422986 3808640 YM1 Atascadero Fm AT NC Kuu York Mountain 10 693802 3938691 YM3 Atascadero Fm AT NC Kuu York Mountain 10 698076 3934762 YM4 Atascadero Fm AT NC Klu Atascadero 10 707994 3927826 YM5 Atascadero Fm AT NC Kuu Atascadero 10 708429 3929081
*Geographic area as defined in Figure 1 of main text. AT—Atascadero; BL—Ben Lomond Mountain; CA—Cambria; CP—Cajon Pass; DP—Del Puerto Canyon; IR—Indians Ranch; LP—La Panza Range; OR—Orocopia Mountains; PL—Point Lobos; PM—Pine Mountain block; PP—Pigeon Point; PS—Point Sur; PSP—Point San Pedro; SG—San Gabriel block; SL—Northwest Santa Lucia Range; SM—Santa Monica Mountains-Simi Hills; SMM—Sierra Madre Mountains; SR—San Rafael Mountains; SY—Santa Ynez Mountains. Descriptions of the areas are provided in the section of the Data Repository item entitled “Geologic Summaries of Forearc Sampling Areas and Notes on Individual Samples.”
†Geographic group as defined in Figure DR2. NC—north-central; NW—northwest; SC—south-central. §Age group as defined in main text. Eoc—early to middle Eocene, Klu—Cenomanian-Turonian; KP—middle Maastrichtian-Paleocene; Kuu—
Campanian-early Maastrichtian. #U.S. Geological Survey 7.5’ topographic quadrangle map. **Samples 03-04 and MO1 from the lower Eocene(?) Carmelo Formation were plotted in the middle Maastrichtian-Paleocene age group for reasons
discussed in the section of the Data Repository item entitled “Geologic Summaries of Forearc Sampling Areas and Notes on Individual Samples.” ††This sample is from the type Great Valley Group of central California east of the San Andreas fault and is not included in the groupings with the rest of
our samples (see explanation in main text). §§ Sample LP3 is located in the southernmost San Rafael Mountains, immediately north of the Santa Ynez fault. The Eocene section of this area bears
strong resemblance to that of the Santa Ynez Mountains south of the Santa Ynez fault. For this reason, we included LP3 in the Eocene group from the Santa Ynez Mountains, rather than plotting it as a lone sample (with only 15 analyses) from the San Rafael Mountains.
TABLE DR3. GROUPINGS BY AGE AND GEOGRAPHIC LOCATION OF FOREARC SEDIMENTARY SAMPLES ANALYZED FOR DETRITAL ZIRCON AGES
Age* Group†
NW NC SC SE
Eoc Ben Lomond Mountain – BB1 Indians Ranch – IR3, IR4
Orocopia Mts. – OR432, OR433 Pine Mountain block – LV2, LV3 Sierra Madre Mts. – MP1, MP2, MP3
Santa Ana Mts. – L Santiago, U Santiago Santa Monica Mts.-Simi Hills – SH6, SM6,
SM6A Santa Ynez Mts. – LP3§, LP7, LP13, LP14,
LP15
Northern Baja – L Las Palmas, M Las Palmas, U Las Palmas
San Diego – Delmar-Bathtub Rock, Scripps-Pat, Scripps-Tourm Bch, Stadium Cgl
San Miguel Island – SMI6
Mid Maast-Pal (KP)
Indians Ranch – IR1, IR5 Point Lobos – 03-04, MO1# Point San Pedro – MM1, MM1A, MM2, MM3 Northwest Santa Lucia Range – ES1, PS1,
PT1
Cajon Pass – SF3 La Panza Range – PZ1, PZ3, PZ4, SML1 San Gabriel block – SF1, SF2, SF4, SF5, VA1
Santa Ana Mts. – L Silverado, U Silverado Santa Monica Mts.-Simi Hills – SH2, SH8,
SM2, SM4
San Diego – Mt. Soledad-EPTM, Mt. Soledad Northern Baja – Cantamar
Camp-early Maast (Kuu)
Pigeon Point – PP1, PP2, PP3 Atascadero – 99-68, YM1, YM3, YM5 Cambria – 03-01, 03-03, 99-66A Point Sur – BS1, BS1A, PS2 San Rafael Mts. – LP1, LP9, TP1
Santa Ana Mts. – Mustang, Williams Santa Monica Mts.-Simi Hills – SH1, SH7,
SM3, SM8 Santa Ynez Mts. – LP12, LP21
Northern Baja – Medano, Rosario-Salsipuedes
San Diego – Rosario-Bird Rock, Rosario-Carlsbad, Rosario-La Jolla Bay, Rosario-Tourm Bch
San Miguel Island – SMI3, SMI4
Tur-Sant (Klu)
Atascadero – YM4 San Rafael Mts. – LP10, LP11
Santa Ana Mts. – Trabuco, Baker Canyon Northern Baja – Redonda-Guad-01, Redonda-Guad-02
San Diego – Lusardi-Carlsbad San Miguel Island – SMI1, SMI2
*Age group as defined in main text. Eoc—early to middle Eocene, Klu—Cenomanian-Turonian; KP—middle Maastrichtian-Paleocene; Kuu—Campanian-early Maastrichtian. †Geographic group as defined in Figure DR2. NC—north-central; NW—northwest; SC—south-central; SE—southeast. Individual sampling localities are described in the section of the Data Repository item entitled
“Geologic Summaries of Forearc Sampling Areas and Notes on Individual Samples.” Analytical results and geologic summaries for all samples from the southeast area and those from the Santa Ana Mountains of the Peninsular Ranges are described in Grove et al. (2009).
§Sample LP3 is located in the southernmost San Rafael Mountains, immediately north of the Santa Ynez fault. The Eocene section of this area bears strong resemblance to that of the Santa Ynez Mountains south of the Santa Ynez fault. For this reason, we included LP3 in the Eocene group from the Santa Ynez Mountains, rather than plotting it as a lone sample (with only 15 analyses) from the San Rafael Mountains.
#Samples 03-04 and MO1 from the lower Eocene(?) Carmelo Formation were plotted in the middle Maastrichtian-Paleocene age group for reasons discussed in the section of the Data Repository item entitled “Geologic Summaries of Forearc Sampling Areas and Notes on Individual Samples.”
Table 4
Zircon U-Pb Data Tables
Tables are grouped into four sections: Pelona-Orocopia-Rand Schists analyzed on the ion microprobe at UCLA Pelona-Orocopia-Rand Schists analyzed on the ICPMS at the Univ. of Arizona Forearc sedimentary units analyzed on the ion microprobe at UCLA Forearc sedimentary units analyzed on the ICPMS at the Univ. of Arizona
Zircon U-Pb Data Tables
Pelona-Orocopia-Rand Schists Analyzed with UCLA Ion Microprobe
KE24033 (Orocopia Schist; Orocopia Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
82 ± 2 67 ± 20 95.5 49.4 - 166 109 8.22 204Pb 03-08 83 ± 1 81 ± 6 99.3 88.2 - 711 639 8.57 204Pb 03-11
100 ± 2 74 ± 22 96.1 50.3 - 122 74 8.47 204Pb 03-04 161 ± 3 149 ± 18 98.0 72.3 - 166 111 8.47 204Pb 03-13 164 ± 2 159 ± 10 98.9 83.3 - 242 236 8.41 204Pb 03-05 165 ± 2 155 ± 10 99.0 85.2 - 484 365 8.53 204Pb 03-09 167 ± 2 139 ± 20 97.8 68.1 - 230 144 8.65 204Pb 03-14 170 ± 2 172 ± 6 99.5 92.2 - 665 952 8.38 204Pb 03-01
1363 ± 18 1485 ± 15 99.5 95.8 1665 ± 20 281 92 8.42 204Pb 03-06 1402 ± 20 1402 ± 22 99.2 93.4 1401 ± 46 180 99 8.42 204Pb 03-12 1416 ± 19 1391 ± 18 99.5 95.1 1353 ± 33 140 115 8.49 204Pb 03-10 1570 ± 19 1574 ± 15 99.4 94.9 1580 ± 20 437 54 8.38 204Pb 03-15 1652 ± 15 1675 ± 9 99.9 99.1 1704 ± 10 401 44 8.33 204Pb 03-02 1792 ± 16 1766 ± 9 100.0 99.6 1735 ± 10 884 535 8.52 204Pb 03-07 1879 ± 16 1830 ± 8 100.0 99.9 1774 ± 3 3291 2514 8.34 204Pb 03-03 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.863 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.63; 208Pb/204Pb = 38.63 ##Session 02/18/2007: RSFPb/U = 1.120 x UO+/U+ - 3.534 for UO+/U+ values in the range 8.26< UO+/U+
<8.58. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 0.7%.
KE127021 (Orocopia Schist; Orocopia Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
84 ± 1 79 ± 3 99.2 87.1 - 1138 2381 8.26 204Pb 02-12 84 ± 1 86 ± 6 99.5 92.0 - 480 338 8.39 204Pb 02-05 94 ± 1 93 ± 3 99.8 95.8 - 1875 1034 8.47 204Pb 02-09
159 ± 2 117 ± 8 97.7 64.7 - 571 478 8.41 204Pb 02-14 162 ± 2 161 ± 7 99.4 90.8 - 319 355 8.50 204Pb 02-07 165 ± 2 165 ± 6 99.5 92.7 - 619 569 8.36 204Pb 02-01 171 ± 2 168 ± 4 99.7 95.1 - 886 801 8.38 204Pb 02-11 681 ± 7 872 ± 8 99.8 98.0 1393 ± 16 811 268 8.38 204Pb 02-13
1615 ± 15 1643 ± 10 99.9 99.2 1679 ± 9 610 97 8.45 204Pb 02-08 1669 ± 23 1652 ± 16 99.2 93.7 1631 ± 27 84 51 8.40 204Pb 02-03 1695 ± 22 1702 ± 17 99.8 98.2 1710 ± 21 104 44 8.39 204Pb 02-06 1729 ± 20 1700 ± 18 99.6 96.9 1664 ± 24 349 54 8.61 204Pb 02-10 1763 ± 16 1736 ± 9 100.0 99.7 1705 ± 8 1414 51 8.17 204Pb 02-04 2329 ± 27 2385 ± 15 99.8 98.8 2432 ± 14 155 185 8.44 204Pb 02-02 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.863 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.63; 208Pb/204Pb = 38.63 ##Session 02/18/2007: RSFPb/U = 1.120 x UO+/U+ - 3.534 for UO+/U+ values in the range 8.26< UO+/U+
<8.58. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 0.7%.
KE224031 (Orocopia Schist; Orocopia Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
77 ± 1 81 ± 11 97.8 72.9 - 306 289 8.49 204Pb 03-03 77 ± 1 78 ± 11 98.0 74.4 - 310 197 8.40 204Pb 03-16 81 ± 1 67 ± 9 96.7 57.4 - 537 596 8.59 204Pb 03-06 85 ± 1 93 ± 11 98.5 80.0 - 270 164 8.36 204Pb 03-05 86 ± 7 86 ± 111 87.5 28.3 - 39 25 8.45 204Pb 03-15
100 ± 1 98 ± 12 97.8 71.5 - 326 138 8.53 204Pb 03-01 163 ± 3 166 ± 19 98.5 79.5 - 189 204 8.39 204Pb 03-14 169 ± 2 160 ± 14 98.7 80.5 - 299 288 8.40 204Pb 03-10 170 ± 2 170 ± 8 99.5 92.5 - 568 512 8.47 204Pb 03-07 174 ± 2 169 ± 5 99.6 93.9 - 1273 2213 8.50 204Pb 03-02
561 ± 10 812 ± 13 99.8 98.6 1582 ± 24 497 56 8.57 204Pb 03-11 1169 ± 18 1188 ± 17 99.7 97.0 1224 ± 32 206 200 8.35 204Pb 03-09 1229 ± 11 1212 ± 8 100.0 99.5 1180 ± 9 2142 696 8.47 204Pb 03-08 1379 ± 14 1379 ± 12 99.7 96.8 1378 ± 19 486 123 8.10 204Pb 03-04 1626 ± 19 1625 ± 17 99.5 95.6 1625 ± 30 242 99 8.44 204Pb 03-17 1689 ± 22 1666 ± 17 99.2 93.4 1638 ± 24 222 234 8.22 204Pb 03-12 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.863 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.63; 208Pb/204Pb = 38.63 ##Session 02/18/2007: RSFPb/U = 1.120 x UO+/U+ - 3.534 for UO+/U+ values in the range 8.26< UO+/U+
<8.58. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 0.7%.
OR113 (Orocopia Schist; Orocopia Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
71 ± 1 66 ± 4 99.1 85.4 - 488 246 7.13 204Pb 02 75 ± 2 78 ± 4 99.4 91.1 - 512 233 7.16 204Pb 09 79 ± 2 78 ± 4 99.4 91.0 - 658 344 7.06 204Pb 11 80 ± 2 81 ± 2 99.7 95.6 - 1293 1239 7.12 204Pb 05 89 ± 2 79 ± 8 98.5 77.3 - 267 220 7.03 204Pb 17 93 ± 2 94 ± 3 99.8 96.2 - 589 319 7.30 204Pb 20 94 ± 2 97 ± 4 99.6 93.6 - 528 371 6.97 204Pb 08
104 ± 2 105 ± 4 99.6 94.1 - 440 242 7.12 204Pb 01 107 ± 2 104 ± 3 99.7 95.0 - 1141 1024 7.00 204Pb 03 108 ± 2 102 ± 5 99.2 87.4 - 452 333 7.07 204Pb 22 109 ± 2 104 ± 6 99.1 86.4 - 1424 704 7.10 204Pb 13 165 ± 3 166 ± 6 99.5 92.3 - 224 205 7.28 204Pb 16 211 ± 5 207 ± 8 99.6 93.5 - 270 58 7.22 204Pb 14 279 ± 5 278 ± 5 100.0 99.5 - 4245 1181 7.19 204Pb 04
1200 ± 38 1196 ± 26 99.5 94.7 1187 ± 42 40 46 7.19 204Pb 24 1420 ± 31 1415 ± 20 99.8 98.6 1406 ± 18 118 180 7.11 204Pb 23 1522 ± 37 1612 ± 21 100.0 99.9 1732 ± 9 1682 800 7.77 204Pb 10 1630 ± 24 1670 ± 14 99.7 97.7 1720 ± 15 383 135 7.67 204Pb 07 1674 ± 43 1697 ± 23 99.9 99.6 1725 ± 15 233 111 7.30 204Pb 06 1705 ± 34 1726 ± 31 99.7 97.7 1751 ± 41 137 64 7.15 204Pb 15 1713 ± 41 1700 ± 23 99.9 99.1 1684 ± 12 133 70 7.33 204Pb 12 1831 ± 31 1788 ± 16 100.0 99.8 1739 ± 4 2621 75 7.19 204Pb 18 1888 ± 27 1824 ± 14 100.0 99.8 1751 ± 4 2369 958 7.35 204Pb 21 2007 ± 33 2136 ± 18 100.0 99.8 2262 ± 7 779 378 7.22 204Pb 19 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.709 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.86; 207Pb/204Pb = 15.62; 208Pb/204Pb = 38.63 ##Session 12/23/2005: RSFPb/U = 1.562 x UO+/U+ - 7.181 for UO+/U+ values in the range 6.46< UO+/U+
<7.17. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.7%.
OR312A (Orocopia Schist; Orocopia Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
81 ± 1 81 ± 3 99.7 94.9 - 893 370 7.35 204Pb 06 81 ± 1 84 ± 5 99.1 86.7 - 387 332 7.41 204Pb 13 82 ± 2 77 ± 11 97.6 68.4 - 181 162 7.20 204Pb 10 84 ± 2 84 ± 3 99.5 92.5 - 706 1315 7.20 204Pb 08
168 ± 3 161 ± 7 99.3 88.6 - 329 451 7.13 204Pb 17 170 ± 5 159 ± 21 98.3 76.0 - 205 157 6.88 204Pb 01 171 ± 3 160 ± 7 99.2 87.8 - 317 368 7.17 204Pb 09 179 ± 4 175 ± 4 99.8 96.0 - 1508 1246 6.96 204Pb 18 221 ± 4 222 ± 6 99.8 97.4 - 804 908 7.00 204Pb 05 243 ± 5 243 ± 5 99.9 98.3 - 1062 384 7.08 204Pb 15 245 ± 4 248 ± 4 99.9 98.3 - 989 410 7.18 204Pb 02
1315 ± 38 1446 ± 26 100.0 99.7 1645 ± 25 2454 237 7.78 204Pb 04 1391 ± 26 1386 ± 15 99.8 97.9 1377 ± 16 156 89 7.35 204Pb 14 1465 ± 29 1437 ± 17 99.8 98.4 1397 ± 10 252 89 7.16 204Pb 12 1663 ± 25 1677 ± 16 99.9 98.9 1694 ± 10 360 132 7.30 204Pb 16 1665 ± 29 1661 ± 16 100.0 99.6 1656 ± 4 1964 150 7.15 204Pb 11 1818 ± 37 1781 ± 22 99.8 98.8 1739 ± 13 123 61 7.06 204Pb 07 1850 ± 29 1803 ± 15 100.0 99.9 1748 ± 3 3851 1547 7.25 204Pb 03 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.709 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.86; 207Pb/204Pb = 15.62; 208Pb/204Pb = 38.63 ##Session 12/23/2005: RSFPb/U = 1.562 x UO+/U+ - 7.181 for UO+/U+ values in the range 6.46< UO+/U+
<7.17. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.7%.
OR314 (Orocopia Schist; Orocopia Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
78 ± 2 70 ± 11 97.5 66.7 - 140 163 7.27 204Pb 05 82 ± 2 73 ± 11 98.0 71.1 - 176 225 7.05 204Pb 10 84 ± 2 82 ± 5 99.2 87.9 - 591 540 6.78 204Pb 01
169 ± 3 161 ± 7 99.5 91.3 - 266 331 7.14 204Pb 03 169 ± 4 168 ± 4 99.7 95.3 - 1133 1673 7.06 204Pb 11 251 ± 6 247 ± 6 99.7 95.5 - 450 161 7.06 204Pb 02 258 ± 6 264 ± 6 99.9 98.1 - 644 226 6.91 204Pb 09
1382 ± 25 1393 ± 17 99.7 97.3 1411 ± 23 489 349 7.15 204Pb 12 1671 ± 35 1710 ± 20 100.0 99.8 1759 ± 8 1377 662 7.09 204Pb 06 1688 ± 35 1665 ± 19 99.7 97.9 1636 ± 17 199 76 7.13 204Pb 07 1725 ± 29 1722 ± 16 100.0 99.7 1718 ± 5 1652 49 7.08 204Pb 08 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.709 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.86; 207Pb/204Pb = 15.62; 208Pb/204Pb = 38.63 ##Session 12/23/2005: RSFPb/U = 1.562 x UO+/U+ - 7.181 for UO+/U+ values in the range 6.46< UO+/U+
<7.17. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.7%.
SE1B (Rand Schist; San Emigdio Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
97 ± 3 98 ± 6 99.4 90.4 - 818 334 9.46 208Pb 21 97 ± 3 110 ± 9 99.1 87.9 - 251 137 9.51 208Pb 22 98 ± 3 104 ± 5 99.7 94.7 - 444 110 9.25 208Pb 05 99 ± 4 102 ± 11 98.5 79.7 - 159 73 9.55 208Pb 17
100 ± 4 110 ± 9 99.3 89.7 - 382 188 9.34 208Pb 14 102 ± 4 104 ± 8 99.1 86.9 - 448 223 9.18 208Pb 23 103 ± 4 101 ± 7 98.0 73.7 - 384 46 9.23 208Pb 02 107 ± 5 106 ± 7 99.0 84.5 - 379 100 9.11 208Pb 12 107 ± 5 102 ± 18 98.2 75.3 - 231 94 9.12 208Pb 24 108 ± 4 99 ± 10 98.5 78.2 - 270 60 9.03 208Pb 20 108 ± 4 103 ± 9 98.7 80.7 - 419 48 8.98 208Pb 11 109 ± 4 104 ± 5 98.7 80.6 - 603 205 9.04 208Pb 01 110 ± 4 109 ± 6 99.2 88.4 - 757 127 8.95 208Pb 07 113 ± 5 119 ± 14 96.9 66.0 - 147 9 8.75 208Pb 08 114 ± 4 120 ± 7 99.8 96.4 - 517 216 9.27 208Pb 15 117 ± 7 116 ± 19 97.2 66.9 - 215 100 8.67 208Pb 25 153 ± 5 155 ± 7 99.7 94.9 - 439 81 9.19 208Pb 04 161 ± 6 161 ± 7 99.5 92.8 - 780 35 9.11 208Pb 09 205 ± 8 185 ± 18 98.6 79.4 - 422 496 9.29 208Pb 19
595 ± 24 597 ± 21 99.8 97.1 606 ± 45 412 135 8.81 208Pb 18 630 ± 20 743 ± 20 99.6 95.6 1100 ± 38 360 259 9.68 204Pb 10 929 ± 39 1051 ± 34 99.4 94.6 1313 ± 50 118 47 9.25 204Pb 13 998 ± 36 1003 ± 25 99.9 98.8 1013 ± 19 270 140 9.05 204Pb 06 1661 ± 56 1675 ± 31 99.9 99.6 1693 ± 10 579 128 9.15 204Pb 03 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.924 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.86; 207Pb/204Pb = 15.62; 208Pb/204Pb = 38.34 ##Session 12/23/2005: RSFPb/U = 2.334 x UO+/U+ - 14.333 for UO+/U+ values in the range 8.46< UO+/U+
<9.28. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 2.6%.
Zircon U-Pb Data Tables
Pelona-Orocopia-Rand Schists Analyzed with University of Arizona LA-ICPMS
CD9 (Orocopia Schist; Castle Dome Mountains)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
CD9-2 388 686 2.2 0.0654 15.1 0.0108 4.9 0.32 69.5 3.4 64.3 9.4 -124.2 354.4 69.5 3.4CD9-5 975 11663 1.3 0.1683 3.9 0.0249 3.5 0.91 158.8 5.6 158.0 5.7 145.2 37.1 158.8 5.6CD9-1 1729 144868 27.3 3.5576 1.9 0.2548 1.4 0.74 1462.9 18.3 1540.1 15.1 1647.8 23.9 1647.8 23.9CD9-4 172 7127 1.1 4.2671 8.8 0.2861 6.3 0.71 1622.0 90.0 1687.0 72.8 1768.9 113.8 1768.9 113.8
MW10 (Orocopia Schist; Marcus Wash Area)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
MW10-20 295 1732 1.7 0.1063 4.1 0.0154 1.9 0.47 98.8 1.9 102.6 4.0 192.1 85.2 98.8 1.9MW10-3 787 1277 0.7 0.2031 13.6 0.0228 4.3 0.31 145.4 6.2 187.7 23.4 760.3 274.1 145.4 6.2MW10-4 214 1905 0.6 0.1933 10.0 0.0240 8.2 0.82 153.0 12.4 179.4 16.5 542.9 126.5 153.0 12.4MW10-2 208 2090 0.8 0.1904 12.9 0.0253 4.1 0.32 160.8 6.5 177.0 21.0 398.3 275.7 160.8 6.5MW10-18 917 2395 1.1 0.2078 4.0 0.0267 2.8 0.71 169.9 4.8 191.7 6.9 469.2 61.7 169.9 4.8MW10-13 1021 17404 2.7 0.2577 2.5 0.0368 2.3 0.91 232.9 5.2 232.8 5.1 232.1 23.3 232.9 5.2MW10-9 70 8082 1.6 2.0744 1.8 0.1899 1.0 0.55 1121.0 10.3 1140.4 12.5 1177.5 30.3 1177.5 30.3MW10-19 619 39068 2.8 2.1288 2.5 0.1939 2.3 0.92 1142.2 24.4 1158.2 17.5 1188.2 19.8 1188.2 19.8MW10-12 68 6536 1.2 2.1590 2.9 0.1961 2.4 0.84 1154.4 25.8 1168.0 20.2 1193.1 31.2 1193.1 31.2MW10-11 109 7667 1.2 2.1694 2.3 0.1954 2.0 0.89 1150.5 21.4 1171.3 15.9 1210.0 20.7 1210.0 20.7MW10-5 289 21908 1.0 2.1631 5.7 0.1869 5.0 0.87 1104.8 50.3 1169.3 39.6 1290.7 54.8 1290.7 54.8MW10-14 182 18862 2.5 2.9493 1.4 0.2364 1.0 0.71 1368.0 12.6 1394.7 10.9 1435.6 19.2 1435.6 19.2MW10-8 289 9095 2.2 2.5461 6.3 0.1969 5.9 0.94 1158.4 62.3 1285.3 45.7 1504.1 40.5 1504.1 40.5MW10-10 2374 143338 3.4 3.8476 3.7 0.2821 2.8 0.75 1602.1 39.3 1602.8 29.6 1603.7 45.0 1603.7 45.0MW10-6 89 15331 1.7 4.0824 1.6 0.2865 1.2 0.76 1624.0 16.9 1650.8 12.6 1685.0 18.6 1685.0 18.6MW10-17 264 16498 3.6 3.3367 15.8 0.2298 15.8 1.00 1333.5 190.3 1489.7 124.4 1719.7 22.9 1719.7 22.9MW10-7 969 129973 21.7 4.5697 2.5 0.3105 2.3 0.92 1743.1 34.7 1743.8 20.7 1744.5 18.3 1744.5 18.3MW10-16 722 46195 1.6 4.4795 3.4 0.2965 3.3 0.96 1673.8 48.6 1727.2 28.6 1792.5 18.3 1792.5 18.3
NR1 (Orocopia Schist; Neversweat Ridge)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
NR1-14 416 2416 0.8 0.0867 5.6 0.0121 3.3 0.59 77.3 2.5 84.4 4.5 289.0 103.5 77.3 2.5NR1-6 444 1536 1.1 0.0996 24.8 0.0121 4.0 0.16 77.7 3.1 96.4 22.8 589.6 538.2 77.7 3.1NR1-2 650 929 1.6 0.1186 23.4 0.0131 7.9 0.34 83.7 6.6 113.8 25.3 800.4 467.9 83.7 6.6NR1-1 1610 5130 4.5 0.1105 6.3 0.0157 2.3 0.36 100.5 2.2 106.4 6.4 240.4 136.8 100.5 2.2NR1-18 853 2700 3.5 0.1309 23.6 0.0159 3.1 0.13 101.6 3.1 124.9 27.8 594.3 514.4 101.6 3.1NR1-19 823 8728 1.1 0.1528 3.1 0.0228 2.8 0.91 145.0 4.0 144.4 4.1 134.1 30.4 145.0 4.0NR1-16 466 5554 1.2 0.1888 2.7 0.0258 1.6 0.62 163.9 2.7 175.6 4.3 336.1 47.5 163.9 2.7NR1-11 272 3977 1.0 0.1914 2.7 0.0262 1.8 0.67 166.8 2.9 177.8 4.4 326.5 45.2 166.8 2.9NR1-17 447 1822 1.5 0.1970 9.8 0.0268 2.8 0.29 170.5 4.7 182.5 16.4 341.9 212.6 170.5 4.7NR1-12 1747 34123 4.3 0.2296 2.1 0.0329 1.8 0.87 208.4 3.7 209.9 3.9 226.8 23.4 208.4 3.7NR1-3 30 2960 1.8 2.3481 3.2 0.1998 2.0 0.63 1174.0 21.5 1227.0 22.6 1321.3 47.5 1321.3 47.5NR1-4 577 42685 1.4 2.8430 2.4 0.2313 2.2 0.91 1341.5 26.3 1367.0 18.0 1406.9 19.2 1406.9 19.2NR1-10 259 26849 3.1 2.9714 2.8 0.2377 2.2 0.78 1374.9 27.2 1400.3 21.3 1439.3 33.3 1439.3 33.3NR1-20 424 44423 6.8 3.5146 9.7 0.2669 9.3 0.95 1525.1 125.9 1530.5 77.0 1538.0 54.9 1538.0 54.9NR1-5 144 18739 2.2 4.0232 3.2 0.2846 3.1 0.95 1614.5 43.8 1638.9 26.2 1670.3 18.6 1670.3 18.6NR1-9 86 12791 1.4 4.1276 1.9 0.2902 1.6 0.85 1642.7 23.7 1659.8 15.7 1681.4 18.5 1681.4 18.5NR1-13 296 28157 2.0 4.1802 2.3 0.2887 2.0 0.87 1634.9 29.0 1670.2 19.0 1714.7 21.4 1714.7 21.4NR1-7 560 41029 2.0 4.3750 1.5 0.3001 1.2 0.76 1692.0 17.3 1707.6 12.7 1726.8 18.4 1726.8 18.4NR1-15 391 45759 2.7 4.3402 1.7 0.2942 1.3 0.74 1662.3 18.6 1701.0 14.2 1749.0 21.3 1749.0 21.3NR1-8 265 33030 2.1 4.7016 3.9 0.2999 1.6 0.42 1690.6 24.3 1767.5 32.7 1859.7 64.0 1859.7 64.0
OR15A (Orocopia Schist; Orocopia Mountains)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
OR15A-1 502 2296 2.4 0.0883 11.8 0.0112 8.1 0.69 71.8 5.8 85.9 9.7 499.1 189.3 71.8 5.8OR15A-4 555 2372 1.8 0.0884 6.6 0.0113 4.5 0.68 72.7 3.2 86.0 5.4 473.6 105.9 72.7 3.2OR15A-3 330 1740 4.8 0.0951 9.9 0.0115 6.4 0.65 73.6 4.7 92.2 8.7 605.8 162.8 73.6 4.7OR15A-11 825 2605 1.9 0.0895 10.3 0.0117 4.1 0.40 74.9 3.1 87.1 8.6 434.5 210.0 74.9 3.1OR15A-6 885 4943 2.8 0.0924 3.5 0.0124 2.4 0.69 79.3 1.9 89.8 3.0 378.9 56.9 79.3 1.9OR15A-5 633 3761 1.7 0.0952 6.3 0.0124 5.4 0.86 79.6 4.3 92.4 5.6 437.0 72.7 79.6 4.3OR15A-14 489 2729 5.6 0.0940 7.0 0.0131 5.9 0.84 83.9 4.9 91.2 6.1 288.8 86.5 83.9 4.9OR15A-7 1297 6174 2.1 0.0925 2.5 0.0135 1.3 0.54 86.2 1.2 89.9 2.1 188.8 48.3 86.2 1.2OR15A-9 438 3017 3.0 0.0994 4.2 0.0135 2.4 0.57 86.5 2.0 96.3 3.8 346.2 77.0 86.5 2.0OR15A-2 449 3260 3.3 0.1088 2.7 0.0146 1.5 0.56 93.3 1.4 104.8 2.7 376.6 50.3 93.3 1.4OR15A-15 269 2398 1.8 0.1445 6.8 0.0193 3.3 0.48 123.3 4.0 137.1 8.8 383.4 135.0 123.3 4.0OR15A-8 1445 127985 27.2 3.4834 2.4 0.2493 2.2 0.91 1435.0 28.5 1523.5 19.2 1648.6 18.5 1648.6 18.5OR15A-10 520 40189 1.5 3.1076 11.9 0.2186 11.5 0.97 1274.4 132.5 1434.6 91.4 1680.7 56.9 1680.7 56.9OR15A-12 737 62637 7.7 3.0889 10.8 0.2115 10.6 0.98 1237.0 119.0 1429.9 82.7 1730.0 36.5 1730.0 36.5
OR77B (Orocopia Schist; Orocopia Mountains)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
OR77B-15 523 2653 1.8 0.0940 4.6 0.0129 1.9 0.42 82.6 1.6 91.2 4.0 323.9 94.7 82.6 1.6OR77B-7 755 3556 5.6 0.0997 5.4 0.0135 3.9 0.72 86.2 3.3 96.5 5.0 359.3 85.6 86.2 3.3OR77B-5 997 4980 3.2 0.0987 4.3 0.0139 1.6 0.38 88.8 1.4 95.5 3.9 266.2 90.3 88.8 1.4OR77B-10 979 5097 2.0 0.0988 19.3 0.0139 6.3 0.33 89.3 5.6 95.7 17.7 258.6 422.6 89.3 5.6OR77B-1 1338 9419 3.5 0.1021 3.0 0.0154 2.4 0.80 98.8 2.4 98.7 2.8 98.6 42.4 98.8 2.4OR77B-6 782 4783 2.1 0.1159 2.2 0.0159 1.7 0.74 101.9 1.7 111.4 2.4 317.8 34.3 101.9 1.7OR77B-3 1064 6838 3.3 0.1049 3.4 0.0166 3.0 0.89 105.9 3.1 101.3 3.2 -5.8 36.5 105.9 3.1OR77B-12 1194 8257 2.2 0.1180 2.8 0.0176 2.5 0.88 112.3 2.8 113.2 3.0 133.2 31.8 112.3 2.8OR77B-4 73 585 1.8 0.1299 21.2 0.0187 3.8 0.18 119.5 4.5 124.0 24.8 212.3 489.0 119.5 4.5OR77B-2 189 1413 2.2 0.2025 37.6 0.0224 7.9 0.21 142.6 11.2 187.3 64.3 795.3 795.8 142.6 11.2OR77B-8 389 4605 3.7 0.1754 3.0 0.0242 1.9 0.62 154.4 2.9 164.1 4.6 305.5 54.7 154.4 2.9OR77B-14 650 3726 1.1 0.1800 4.8 0.0251 2.9 0.62 159.7 4.6 168.1 7.4 287.9 85.8 159.7 4.6OR77B-11 535 14077 3.2 0.4810 1.8 0.0627 1.5 0.81 392.3 5.5 398.8 5.9 436.6 23.7 392.3 5.5OR77B-13 586 38708 2.6 2.7438 2.2 0.2256 2.0 0.89 1311.5 23.8 1340.4 16.7 1386.9 19.2 1386.9 19.2OR77B-9 609 17417 3.3 1.6342 10.7 0.1187 10.5 0.98 723.3 71.7 983.5 67.5 1620.8 40.2 1620.8 40.2
OR307 (Orocopia Schist; Orocopia Mountains)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
OR307-1 141 1140 4.2 0.0996 6.9 0.0138 3.2 0.46 88.4 2.8 96.4 6.3 299.2 139.6 88.4 2.8OR307-8 1323 6446 1.7 0.1002 3.6 0.0144 2.2 0.60 91.9 2.0 97.0 3.3 224.5 66.0 91.9 2.0OR307-15 350 2682 2.0 0.1042 3.8 0.0145 2.6 0.68 93.0 2.4 100.6 3.7 284.5 64.7 93.0 2.4OR307-5 329 2809 2.2 0.1095 8.9 0.0148 3.9 0.43 94.6 3.6 105.5 8.9 357.9 181.4 94.6 3.6OR307-9 437 3356 2.6 0.1162 5.1 0.0158 2.7 0.54 101.1 2.7 111.6 5.4 341.0 97.0 101.1 2.7OR307-4 189 1759 2.2 0.1161 7.9 0.0159 1.8 0.23 101.6 1.8 111.6 8.4 330.7 174.9 101.6 1.8OR307-10 1194 10572 2.4 0.1114 2.2 0.0169 1.2 0.55 108.1 1.3 107.2 2.2 87.2 43.9 108.1 1.3OR307-6 432 4683 11.5 0.1294 3.6 0.0176 2.5 0.69 112.7 2.7 123.5 4.2 338.1 58.9 112.7 2.7OR307-7 470 52606 4.2 2.8033 1.5 0.2320 1.1 0.73 1345.1 12.9 1356.4 10.9 1374.2 19.2 1374.2 19.2OR307-13 611 45863 5.5 2.5197 7.2 0.1947 7.2 0.99 1146.7 75.2 1277.7 52.6 1505.4 18.9 1505.4 18.9OR307-2 170 18566 2.3 3.4819 2.0 0.2539 1.7 0.86 1458.6 22.0 1523.1 15.5 1613.9 18.7 1613.9 18.7OR307-12 611 69604 2.9 4.0441 3.0 0.2833 1.6 0.52 1608.0 22.4 1643.1 24.5 1688.3 47.4 1688.3 47.4OR307-11 347 51808 3.7 4.3912 1.4 0.2998 1.0 0.71 1690.2 14.9 1710.7 11.7 1735.8 18.3 1735.8 18.3OR307-3 323 50516 2.1 4.6646 5.1 0.3044 4.9 0.95 1713.3 73.2 1760.9 42.8 1817.9 28.9 1817.9 28.9OR307-14 417 36038 2.3 6.1658 2.2 0.2508 1.9 0.89 1442.7 25.2 1999.6 19.1 2637.0 16.6 2637.0 16.6
OR337 (Orocopia Schist; Orocopia Mountains)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
OR337-5 111 624 1.1 0.0627 15.0 0.0112 6.3 0.42 71.8 4.5 61.8 9.0 -309.9 351.0 71.8 4.5OR337-15 302 1838 1.9 0.0823 7.0 0.0124 4.5 0.64 79.2 3.5 80.3 5.4 113.2 127.7 79.2 3.5OR337-6 316 1484 1.6 0.0840 22.5 0.0125 4.0 0.18 79.9 3.2 81.9 17.7 138.8 525.5 79.9 3.2OR337-3 288 1764 1.6 0.0902 13.1 0.0129 4.0 0.31 82.3 3.3 87.7 11.0 236.3 289.5 82.3 3.3OR337-1 256 1524 1.5 0.0846 7.5 0.0129 4.9 0.66 82.8 4.1 82.5 5.9 72.0 133.4 82.8 4.1OR337-8 259 1205 1.1 0.1031 11.2 0.0133 3.4 0.30 85.0 2.9 99.7 10.6 467.1 236.6 85.0 2.9OR337-13 529 4367 7.3 0.0981 4.6 0.0137 2.3 0.50 87.8 2.0 95.0 4.2 279.8 91.6 87.8 2.0OR337-11 756 5475 3.2 0.1045 2.9 0.0145 2.2 0.76 92.7 2.1 100.9 2.8 300.3 43.1 92.7 2.1OR337-4 502 3922 3.1 0.1046 3.7 0.0151 2.5 0.69 96.4 2.4 101.0 3.5 210.3 62.1 96.4 2.4OR337-14 245 1483 1.1 0.1094 7.1 0.0161 3.5 0.48 103.1 3.5 105.4 7.2 156.9 146.4 103.1 3.5OR337-9 364 1325 1.4 0.3601 8.2 0.0431 3.0 0.36 272.3 7.9 312.3 22.0 622.7 164.4 272.3 7.9OR337-12 529 27592 2.9 1.0972 3.9 0.1094 3.4 0.89 669.2 21.9 752.0 20.7 1006.8 36.8 1006.8 36.8OR337-2 528 17190 4.1 1.8071 7.1 0.1731 6.9 0.97 1029.4 65.2 1048.0 46.3 1087.0 35.3 1087.0 35.3OR337-10 487 17093 4.7 1.7165 5.8 0.1564 5.7 0.98 936.9 49.9 1014.7 37.5 1186.7 23.1 1186.7 23.1OR337-7 1047 124314 2.3 4.4055 5.1 0.2993 5.0 0.98 1688.0 74.2 1713.4 42.2 1744.5 18.3 1744.5 18.3
PK114B (Orocopia Schist; Peter Kane Mountain)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
PK114B-16 1045 3456 2.6 0.0536 10.8 0.0072 10.0 0.92 46.4 4.6 53.0 5.6 364.2 95.9 46.4 4.6PK114B-7 745 1011 2.1 0.1155 11.8 0.0123 3.0 0.26 78.9 2.4 111.0 12.4 869.4 237.6 78.9 2.4PK114B-20 517 2699 2.2 0.0874 3.4 0.0124 1.8 0.52 79.3 1.4 85.1 2.8 249.3 66.8 79.3 1.4PK114B-12 681 1992 0.6 0.0983 20.5 0.0124 4.7 0.23 79.5 3.7 95.2 18.7 509.2 443.7 79.5 3.7PK114B-10 487 3796 2.5 0.0937 5.5 0.0124 4.2 0.77 79.8 3.3 91.0 4.7 396.4 78.6 79.8 3.3PK114B-14 405 2340 1.8 0.1023 3.8 0.0132 2.5 0.65 84.5 2.1 98.9 3.6 461.6 63.9 84.5 2.1PK114B-6 417 2698 1.2 0.0904 9.5 0.0133 4.0 0.42 85.0 3.4 87.9 8.0 166.3 202.8 85.0 3.4PK114B-18 342 3058 1.8 0.1037 7.3 0.0134 3.4 0.46 85.8 2.9 100.2 7.0 457.9 144.3 85.8 2.9PK114B-9 258 985 1.9 0.1168 17.0 0.0135 4.8 0.28 86.6 4.1 112.1 18.0 696.5 349.5 86.6 4.1PK114B-15 265 2180 2.4 0.1069 7.0 0.0135 1.5 0.22 86.6 1.3 103.1 6.9 504.4 150.7 86.6 1.3PK114B-11 629 4964 1.7 0.0996 4.9 0.0136 4.2 0.84 87.0 3.6 96.4 4.5 336.0 60.2 87.0 3.6PK114B-19 925 3579 10.4 0.1094 7.6 0.0158 7.2 0.95 100.8 7.2 105.4 7.6 210.6 57.2 100.8 7.2PK114B-2 170 2653 3.0 0.1516 5.8 0.0211 3.8 0.65 134.3 5.1 143.3 7.8 294.5 100.5 134.3 5.1PK114B-8 292 5053 2.6 0.2114 5.0 0.0293 2.3 0.46 185.9 4.2 194.7 8.8 302.7 100.5 185.9 4.2PK114B-4 367 1857 3.3 0.2541 18.9 0.0297 4.8 0.25 189.0 8.9 229.9 38.8 672.2 393.5 189.0 8.9PK114B-1 848 107922 6.6 4.1382 3.3 0.2912 3.0 0.93 1647.4 44.3 1661.9 26.9 1680.2 22.7 1680.2 22.7PK114B-17 460 54387 1.6 4.1138 2.7 0.2873 2.2 0.79 1627.8 31.1 1657.1 22.4 1694.3 31.0 1694.3 31.0
PM1 (Pelona Schist; Mount Pinos)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
PM1-16 576 4566 1.1 0.0736 5.8 0.0125 2.5 0.44 80.2 2.0 72.1 4.0 -190.5 130.1 80.2 2.0PM1-12 200 1331 3.0 0.0444 32.1 0.0130 4.5 0.14 83.2 3.7 44.1 13.9 -1786.4 1152.9 83.2 3.7PM1-15 408 2297 1.5 0.0831 7.6 0.0130 2.6 0.35 83.4 2.2 81.0 5.9 11.0 170.6 83.4 2.2PM1-13 643 2832 1.3 0.0877 4.2 0.0132 2.0 0.47 84.2 1.6 85.3 3.4 115.4 87.3 84.2 1.6PM1-20 292 1355 1.7 0.0750 8.1 0.0133 5.7 0.71 85.0 4.8 73.4 5.7 -289.5 145.1 85.0 4.8PM1-8 1343 9915 1.2 0.0799 5.2 0.0133 4.0 0.77 85.5 3.4 78.1 3.9 -142.9 83.0 85.5 3.4PM1-22 265 1691 1.7 0.0696 10.9 0.0137 3.8 0.34 88.0 3.3 68.3 7.2 -576.7 278.4 88.0 3.3PM1-1 1656 12934 4.9 0.0959 7.5 0.0139 4.5 0.60 88.9 4.0 92.9 6.7 199.0 139.7 88.9 4.0PM1-18 235 2668 1.6 0.0805 8.5 0.0140 5.6 0.66 89.8 5.0 78.6 6.5 -250.4 162.7 89.8 5.0PM1-23 1185 7120 2.1 0.0893 5.9 0.0145 5.3 0.90 92.9 4.9 86.9 4.9 -75.8 64.3 92.9 4.9PM1-24 110 1878 1.9 0.0551 185.4 0.0146 6.4 0.03 93.3 6.0 54.5 98.6 -1447.1 0.0 93.3 6.0PM1-11 521 2483 1.8 0.1131 24.4 0.0150 2.7 0.11 96.3 2.6 108.8 25.2 392.3 551.2 96.3 2.6PM1-9 1722 14313 3.6 0.0936 5.3 0.0153 3.5 0.66 97.8 3.4 90.9 4.6 -87.7 97.9 97.8 3.4PM1-10 698 11808 5.8 0.1069 3.0 0.0162 2.1 0.71 103.4 2.2 103.1 2.9 95.9 49.7 103.4 2.2PM1-14 293 2625 0.7 0.1037 5.8 0.0167 3.2 0.56 106.9 3.4 100.2 5.6 -57.4 117.8 106.9 3.4PM1-4 123 2278 1.0 0.1198 13.8 0.0222 5.4 0.39 141.9 7.5 114.9 15.0 -413.7 334.3 141.9 7.5PM1-6 120 1821 1.2 0.0848 21.1 0.0225 5.6 0.26 143.3 7.9 82.6 16.7 -1452.5 672.7 143.3 7.9PM1-19 428 4681 1.3 0.1548 7.2 0.0228 3.6 0.50 145.3 5.2 146.1 9.8 159.3 145.3 145.3 5.2PM1-5 110 883 1.6 0.1716 23.2 0.0232 4.8 0.20 147.6 6.9 160.8 34.5 360.5 518.5 147.6 6.9PM1-25 432 4317 1.0 0.1662 3.9 0.0242 2.9 0.73 154.0 4.3 156.1 5.6 188.0 61.6 154.0 4.3PM1-17 211 3444 0.8 0.1533 6.1 0.0245 3.7 0.61 155.9 5.7 144.8 8.2 -32.9 115.9 155.9 5.7PM1-7 570 16894 1.1 0.2494 2.8 0.0365 2.3 0.82 231.0 5.2 226.1 5.7 175.9 37.3 231.0 5.2PM1-3 282 10747 1.7 0.2848 4.9 0.0403 2.0 0.41 254.4 4.9 254.5 11.0 255.0 102.7 254.4 4.9PM1-2 146 5043 1.7 0.2718 5.3 0.0404 3.2 0.60 255.2 8.0 244.1 11.6 138.6 99.9 255.2 8.0PM1-21 157 7742 1.2 1.8410 4.8 0.1753 2.9 0.59 1041.5 27.4 1060.2 31.7 1098.9 77.6 1041.5 27.4
PM3 (Pelona Schist; Mount Pinos)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
PM3-02 264 1428 0.8 0.0522 12.3 0.0116 3.9 0.32 74.3 2.9 51.7 6.2 -902.5 338.7 74.3 2.9PM3-04 273 1679 0.8 0.0574 11.7 0.0125 4.0 0.34 80.0 3.2 56.7 6.5 -842.6 315.9 80.0 3.2PM3-18 456 4326 1.2 0.0688 6.0 0.0125 3.8 0.63 80.2 3.0 67.6 3.9 -359.1 121.2 80.2 3.0PM3-23 715 6016 1.1 0.0739 8.9 0.0127 4.1 0.46 81.1 3.3 72.4 6.2 -205.8 198.4 81.1 3.3PM3-14 237 2112 0.7 0.0394 36.8 0.0128 4.3 0.12 81.8 3.5 39.3 14.2 -2169.5 1468.6 81.8 3.5PM3-12 891 5474 2.0 0.0812 3.8 0.0128 2.4 0.65 81.8 2.0 79.2 2.9 2.2 69.4 81.8 2.0PM3-24 776 3881 1.1 0.0784 5.5 0.0130 3.4 0.61 83.0 2.8 76.6 4.1 -116.9 108.4 83.0 2.8PM3-21 1129 6607 1.7 0.0803 3.8 0.0131 2.2 0.59 83.7 1.9 78.4 2.9 -78.2 75.8 83.7 1.9PM3-06 424 2596 1.3 0.0772 10.3 0.0133 3.0 0.29 85.2 2.6 75.5 7.5 -219.9 248.3 85.2 2.6PM3-17 486 3337 0.8 0.0826 5.4 0.0137 1.8 0.33 88.0 1.5 80.6 4.2 -133.2 126.0 88.0 1.5PM3-19 283 1928 1.4 0.0684 11.6 0.0140 2.5 0.21 89.5 2.2 67.2 7.6 -670.1 314.8 89.5 2.2PM3-07 1449 7936 1.5 0.0931 7.0 0.0144 4.7 0.66 92.2 4.3 90.4 6.1 43.9 126.0 92.2 4.3PM3-13 603 4028 2.1 0.0926 5.3 0.0145 2.1 0.40 92.5 2.0 89.9 4.6 22.1 116.2 92.5 2.0PM3-08 666 5359 1.8 0.0883 3.5 0.0145 1.8 0.51 93.1 1.7 86.0 2.9 -108.2 74.7 93.1 1.7PM3-05 1777 12808 1.4 0.0959 5.2 0.0148 4.5 0.86 94.7 4.2 92.9 4.7 48.2 64.8 94.7 4.2PM3-03 1355 8288 2.1 0.0968 3.0 0.0154 2.1 0.69 98.8 2.0 93.9 2.7 -28.8 52.3 98.8 2.0PM3-20 607 4047 1.6 0.0996 5.6 0.0159 3.7 0.66 101.4 3.7 96.4 5.2 -26.4 102.9 101.4 3.7PM3-22 521 3574 1.3 0.0988 9.5 0.0163 3.2 0.34 104.2 3.3 95.7 8.7 -110.7 220.1 104.2 3.3PM3-25 105 741 3.5 0.0452 14.9 0.0168 4.8 0.32 107.4 5.1 44.9 6.5 -2740.6 636.7 107.4 5.1PM3-16 103 1916 1.0 0.0794 21.5 0.0221 3.8 0.18 141.1 5.3 77.5 16.1 -1620.9 730.7 141.1 5.3PM3-01 167 1459 1.3 0.1233 11.8 0.0228 5.7 0.48 145.5 8.2 118.0 13.1 -405.5 269.2 145.5 8.2PM3-15 401 2602 1.7 0.1376 11.7 0.0239 4.3 0.36 152.5 6.4 130.9 14.4 -243.9 276.8 152.5 6.4PM3-10 134 2203 1.3 0.3011 12.4 0.0399 3.4 0.27 252.2 8.3 267.3 29.0 401.1 267.2 252.2 8.3PM3-09 146 2555 1.7 0.2637 5.9 0.0406 3.0 0.51 256.4 7.6 237.7 12.6 56.3 122.2 256.4 7.6PM3-11 176 5175 1.6 0.2783 3.9 0.0415 1.8 0.47 261.8 4.7 249.3 8.6 133.1 81.0 261.8 4.7
PM4 (Pelona Schist; Mount Pinos)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
PM4-11 449 637 1.3 0.1123 22.5 0.0121 5.5 0.24 77.6 4.2 108.0 23.0 845.3 458.4 77.6 4.2PM4-12 245 4347 2.1 0.0593 14.3 0.0127 4.7 0.33 81.2 3.8 58.5 8.1 -795.3 383.7 81.2 3.8PM4-7 437 3136 1.4 0.0777 5.5 0.0131 2.6 0.46 84.1 2.1 76.0 4.0 -173.1 122.3 84.1 2.1PM4-18 408 2957 1.6 0.0862 13.9 0.0134 3.5 0.25 85.5 3.0 83.9 11.2 37.7 323.0 85.5 3.0PM4-22 273 4331 1.6 0.0941 7.8 0.0136 3.0 0.38 86.9 2.6 91.3 6.8 208.8 166.9 86.9 2.6PM4-17 405 4984 2.2 0.0856 4.1 0.0140 2.4 0.60 89.4 2.2 83.4 3.3 -86.4 80.4 89.4 2.2PM4-25 261 1859 0.9 0.0801 8.1 0.0141 6.2 0.77 90.0 5.6 78.2 6.1 -269.4 130.9 90.0 5.6PM4-8 910 7938 2.7 0.0965 2.7 0.0147 1.6 0.58 94.2 1.5 93.6 2.4 77.0 52.8 94.2 1.5PM4-2 1050 9104 2.6 0.1005 4.7 0.0147 3.0 0.63 94.3 2.8 97.2 4.3 169.4 84.9 94.3 2.8PM4-1 260 2789 1.7 0.0670 9.4 0.0149 2.1 0.22 95.3 2.0 65.9 6.0 -908.1 265.5 95.3 2.0PM4-4 331 2640 1.7 0.0860 5.4 0.0151 2.6 0.48 96.7 2.5 83.7 4.4 -272.5 121.2 96.7 2.5PM4-15 81 610 3.1 0.0508 24.9 0.0156 4.3 0.17 99.8 4.3 50.3 12.2 -1964.1 920.7 99.8 4.3PM4-24 1139 17774 2.6 0.1010 5.3 0.0156 3.1 0.58 100.1 3.1 97.7 5.0 41.0 104.0 100.1 3.1PM4-23 362 5154 1.5 0.1060 9.3 0.0158 6.9 0.74 100.7 6.9 102.3 9.0 138.6 146.5 100.7 6.9PM4-20 343 5302 3.7 0.1109 5.8 0.0158 4.4 0.75 101.2 4.4 106.8 5.9 232.1 89.8 101.2 4.4PM4-6 345 1323 1.4 0.1301 11.3 0.0180 3.2 0.28 114.7 3.6 124.2 13.2 309.4 247.5 114.7 3.6PM4-9 286 2213 1.9 0.1226 5.7 0.0203 3.0 0.53 129.6 3.8 117.4 6.3 -122.7 119.5 129.6 3.8PM4-3 217 2525 1.2 0.1162 5.9 0.0220 2.6 0.44 140.0 3.6 111.6 6.2 -459.4 139.9 140.0 3.6PM4-10 136 2383 1.1 0.1064 14.0 0.0224 2.9 0.21 142.5 4.2 102.6 13.7 -748.5 385.1 142.5 4.2PM4-16 214 1564 0.9 0.1699 9.2 0.0230 2.5 0.27 146.7 3.6 159.3 13.6 351.1 200.9 146.7 3.6PM4-19 164 2828 1.7 0.1583 6.5 0.0231 3.0 0.46 147.4 4.4 149.2 9.0 177.6 134.8 147.4 4.4PM4-13 49 621 1.8 0.3052 49.7 0.0431 9.4 0.19 271.9 25.0 270.5 118.5 258.5 1187.7 271.9 25.0PM4-5 163 12618 0.9 2.1640 2.2 0.1981 1.9 0.87 1165.0 20.5 1169.6 15.3 1178.1 21.5 1178.1 21.5PM4-14 2099 90607 4.3 4.0486 6.1 0.2664 5.5 0.91 1522.7 74.9 1644.0 49.5 1802.8 46.2 1802.8 46.2
PM9 (Pelona Schist; Mount Pinos)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
PM9-09 259 2444 1.6 0.0817 6.3 0.0151 2.9 0.46 96.5 2.8 79.7 4.8 -398.8 145.7 96.5 2.8PM9-21 492 1355 1.6 0.1387 11.3 0.0163 5.5 0.49 104.5 5.7 131.9 14.0 658.6 212.0 104.5 5.7PM9-24A 593 8842 1.8 0.1085 7.9 0.0168 6.5 0.83 107.5 6.9 104.6 7.8 39.5 105.7 107.5 6.9PM9-15 1023 2201 1.5 0.1412 12.9 0.0171 6.3 0.49 109.0 6.8 134.1 16.2 605.5 244.8 109.0 6.8PM9-02 1121 13362 0.9 0.1020 7.7 0.0171 6.2 0.80 109.3 6.7 98.6 7.2 -152.7 114.0 109.3 6.7PM9-01A 368 4644 2.0 0.1117 2.7 0.0172 1.7 0.63 109.6 1.9 107.6 2.8 61.7 50.2 109.6 1.9PM9-14 235 3554 1.7 0.0985 7.2 0.0174 2.4 0.33 111.4 2.6 95.4 6.6 -290.1 174.8 111.4 2.6PM9-24 1530 17807 50.1 0.1101 13.5 0.0176 13.2 0.98 112.7 14.8 106.1 13.6 -40.7 60.0 112.7 14.8PM9-20 147 889 1.5 0.1168 10.0 0.0179 1.8 0.18 114.7 2.1 112.2 10.6 59.0 234.9 114.7 2.1PM9-10 195 1893 1.3 0.1097 11.3 0.0181 2.3 0.21 115.6 2.7 105.7 11.3 -112.7 272.3 115.6 2.7PM9-08 600 4921 1.9 0.1208 6.0 0.0181 4.6 0.77 115.7 5.3 115.8 6.6 117.1 89.9 115.7 5.3PM9-22 197 1826 1.6 0.1220 6.6 0.0182 3.1 0.47 116.2 3.6 116.9 7.3 131.0 136.6 116.2 3.6PM9-18 512 6493 1.5 0.1223 4.5 0.0187 2.7 0.59 119.4 3.1 117.1 5.0 72.2 85.9 119.4 3.1PM9-13 204 3971 1.4 0.1090 7.2 0.0188 2.1 0.29 120.3 2.5 105.0 7.2 -228.3 174.0 120.3 2.5PM9-11 179 1183 1.8 0.1196 7.3 0.0191 3.2 0.44 121.9 3.9 114.7 7.9 -31.5 158.3 121.9 3.9PM9-16 191 2782 2.8 0.1036 5.2 0.0192 1.9 0.37 122.3 2.3 100.1 5.0 -400.3 126.5 122.3 2.3PM9-25 169 3180 1.2 0.0863 14.8 0.0192 4.2 0.28 122.9 5.1 84.1 11.9 -917.3 414.3 122.9 5.1PM9-05 236 3194 1.8 0.1126 5.8 0.0193 3.5 0.61 123.0 4.3 108.3 6.0 -203.0 115.3 123.0 4.3PM9-04A 254 2734 1.9 0.1108 9.9 0.0196 4.7 0.48 125.1 5.9 106.7 10.0 -285.9 221.0 125.1 5.9PM9-12 291 4967 1.1 0.1276 5.6 0.0205 1.5 0.27 131.0 2.0 121.9 6.4 -51.9 130.9 131.0 2.0PM9-17 147 1336 1.5 0.1251 12.1 0.0205 5.3 0.44 131.1 6.9 119.7 13.6 -102.0 266.6 131.1 6.9PM9-08A 222 1463 0.9 0.1421 4.0 0.0208 3.1 0.77 132.6 4.1 134.9 5.1 176.5 60.1 132.6 4.1PM9-19 218 2577 0.9 0.1032 8.5 0.0208 5.7 0.66 132.9 7.4 99.8 8.1 -634.4 175.1 132.9 7.4PM9-23 413 5824 2.3 0.1406 3.5 0.0208 2.2 0.64 133.0 2.9 133.6 4.4 145.0 62.9 133.0 2.9PM9-03 205 2389 1.9 0.1206 12.8 0.0212 7.7 0.60 135.3 10.4 115.6 14.0 -272.3 259.9 135.3 10.4PM9-06A 249 4396 1.8 0.1200 7.5 0.0212 2.7 0.36 135.4 3.6 115.1 8.1 -286.6 177.5 135.4 3.6PM9-07 128 3522 2.5 0.0937 26.8 0.0220 4.2 0.16 140.3 5.9 91.0 23.3 -1069.0 807.3 140.3 5.9
PM11 (Pelona Schist; Mount Pinos)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
PM11-10 1109 5601 0.8 0.0778 5.2 0.0117 3.8 0.73 74.8 2.8 76.1 3.8 117.1 83.1 74.8 2.8PM11-25 381 1468 1.2 0.0646 8.6 0.0118 3.1 0.36 75.3 2.3 63.5 5.3 -362.3 209.0 75.3 2.3PM11-17 518 2279 1.0 0.0655 8.2 0.0119 3.6 0.44 76.0 2.7 64.4 5.1 -347.1 189.4 76.0 2.7PM11-22 681 2386 0.8 0.0762 8.4 0.0119 3.8 0.45 76.3 2.9 74.6 6.1 20.2 181.0 76.3 2.9PM11-18 861 5400 1.1 0.0765 4.5 0.0121 4.1 0.91 77.7 3.2 74.9 3.2 -12.9 43.9 77.7 3.2PM11-7 1539 7522 0.9 0.0747 3.9 0.0122 2.5 0.63 78.1 1.9 73.2 2.7 -85.1 73.4 78.1 1.9PM11-11 823 5024 0.7 0.0779 3.7 0.0122 3.0 0.81 78.4 2.3 76.1 2.7 5.0 52.6 78.4 2.3PM11-1 397 1975 0.8 0.0679 6.7 0.0128 2.8 0.42 81.9 2.3 66.7 4.3 -450.2 161.6 81.9 2.3PM11-8 427 2131 1.0 0.0654 5.3 0.0128 2.6 0.49 82.2 2.1 64.3 3.3 -559.4 124.0 82.2 2.1PM11-2 387 2728 2.3 0.0817 6.5 0.0130 2.3 0.36 83.0 1.9 79.8 5.0 -16.2 146.7 83.0 1.9PM11-21 1194 5049 1.5 0.0827 4.8 0.0137 3.8 0.79 88.0 3.3 80.6 3.7 -131.0 72.5 88.0 3.3PM11-20 518 839 1.2 0.1129 58.0 0.0138 10.6 0.18 88.5 9.4 108.6 59.8 574.0 1351.8 88.5 9.4PM11-12 325 2032 1.8 0.0694 13.8 0.0139 3.0 0.22 89.1 2.7 68.1 9.1 -617.8 370.1 89.1 2.7PM11-9 555 3588 0.8 0.0915 11.6 0.0142 3.4 0.30 90.7 3.1 88.9 9.9 39.4 265.8 90.7 3.1PM11-23 868 3719 1.8 0.0875 6.8 0.0144 6.4 0.95 91.9 5.9 85.2 5.6 -98.4 53.9 91.9 5.9PM11-4 1423 8665 1.8 0.0927 5.0 0.0144 3.9 0.77 92.1 3.5 90.0 4.3 34.4 75.7 92.1 3.5PM11-13 781 3127 1.8 0.0958 3.3 0.0147 1.7 0.53 94.4 1.6 92.9 2.9 55.6 66.4 94.4 1.6PM11-3 749 4017 1.4 0.1011 10.5 0.0154 5.0 0.48 98.3 4.9 97.8 9.8 85.5 220.2 98.3 4.9PM11-19 1439 7184 2.6 0.0968 2.5 0.0155 1.7 0.68 99.1 1.7 93.8 2.3 -37.1 45.2 99.1 1.7PM11-24 1470 7046 2.0 0.1137 3.5 0.0171 2.5 0.72 109.5 2.8 109.4 3.7 106.2 58.0 109.5 2.8PM11-14 501 3561 1.5 0.1248 3.5 0.0195 2.7 0.79 124.6 3.4 119.4 3.9 16.8 50.5 124.6 3.4PM11-6 777 14293 1.2 0.2771 5.5 0.0392 3.3 0.60 248.0 8.0 248.4 12.1 251.6 101.7 248.0 8.0PM11-5 176 4003 2.4 0.3145 11.0 0.0428 10.6 0.97 270.1 28.2 277.7 26.7 341.8 62.6 270.1 28.2PM11-16 206 40268 0.4 12.7377 7.5 0.5157 6.3 0.84 2681.0 137.5 2660.4 70.5 2644.9 67.7 2644.9 67.7
SE03 (Rand Schist; San Emigdio Mountains)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
SE03-05 184 1598 2.2 0.0818 9.3 0.0159 3.8 0.41 101.6 3.8 79.8 7.1 -533.2 227.6 101.6 3.8SE03-25 228 1437 1.5 0.0919 14.9 0.0161 4.6 0.31 102.8 4.7 89.2 12.8 -260.7 361.5 102.8 4.7SE03-23 512 3782 1.4 0.1042 4.1 0.0164 2.9 0.70 105.1 3.0 100.6 4.0 -3.8 70.7 105.1 3.0SE03-19 503 5734 1.6 0.1053 5.7 0.0165 2.6 0.47 105.5 2.8 101.7 5.5 14.5 120.3 105.5 2.8SE03-11 573 3036 1.5 0.1099 4.4 0.0166 2.9 0.67 106.2 3.1 105.9 4.4 97.7 76.8 106.2 3.1SE03-18 722 3904 1.7 0.1124 6.6 0.0167 2.6 0.39 106.5 2.7 108.2 6.8 145.5 143.2 106.5 2.7SE03-02 547 6592 1.1 0.1110 6.6 0.0167 3.5 0.53 106.5 3.7 106.9 6.7 115.6 131.5 106.5 3.7SE03-01 499 7315 2.6 0.1108 5.4 0.0170 3.7 0.68 108.5 4.0 106.7 5.5 65.7 95.4 108.5 4.0SE03-12 593 4705 2.1 0.1096 4.3 0.0170 2.1 0.48 109.0 2.3 105.6 4.4 29.5 91.3 109.0 2.3SE03-03 221 1438 1.8 0.1062 10.0 0.0171 4.7 0.47 109.0 5.1 102.5 9.8 -46.6 215.6 109.0 5.1SE03-21 243 2910 1.7 0.0897 8.5 0.0171 1.8 0.22 109.1 2.0 87.2 7.1 -477.0 220.0 109.1 2.0SE03-14 233 2277 2.4 0.1099 8.2 0.0172 5.0 0.61 110.0 5.5 105.9 8.2 14.7 155.3 110.0 5.5SE03-08 806 4177 2.3 0.1243 11.1 0.0172 2.8 0.25 110.1 3.0 118.9 12.4 300.2 245.0 110.1 3.0SE03-17 687 6273 1.1 0.1166 4.3 0.0173 2.7 0.63 110.4 3.0 112.0 4.6 147.3 78.7 110.4 3.0SE03-07 292 2720 1.3 0.0937 7.7 0.0175 2.0 0.26 111.7 2.3 91.0 6.7 -422.9 194.9 111.7 2.3SE03-04 932 5649 2.4 0.1126 3.8 0.0175 2.2 0.59 111.8 2.5 108.4 3.9 34.1 73.2 111.8 2.5SE03-09 566 4903 1.4 0.1074 4.3 0.0175 2.6 0.59 112.0 2.8 103.6 4.3 -84.7 86.0 112.0 2.8SE03-06 211 856 1.8 0.0998 10.9 0.0179 4.9 0.45 114.1 5.5 96.6 10.0 -317.7 249.2 114.1 5.5SE03-13 990 6628 3.0 0.1085 2.4 0.0180 1.6 0.66 114.9 1.8 104.6 2.4 -122.5 44.5 114.9 1.8SE03-24 181 456 1.6 0.1886 32.0 0.0183 6.6 0.21 117.1 7.7 175.4 51.6 1059.2 646.0 117.1 7.7SE03-10 511 3328 1.2 0.1663 5.8 0.0247 3.9 0.68 157.1 6.1 156.2 8.4 143.0 99.6 157.1 6.1SE03-22 162 13096 0.7 1.1721 3.8 0.1321 3.3 0.89 799.9 25.1 787.6 20.6 753.0 36.6 799.9 25.1SE03-20 653 64479 4.0 1.9249 3.9 0.1510 3.0 0.77 906.4 25.6 1089.8 26.3 1477.2 47.6 1477.2 47.6
SG69 (Pelona Schist; San Gabriel Mountains)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
SG69-5 688 2749 2.6 0.0965 22.0 0.0107 8.6 0.39 68.5 5.9 93.5 19.6 789.6 428.4 68.5 5.9SG69-3 346 944 1.1 0.1119 25.2 0.0114 4.5 0.18 73.2 3.3 107.7 25.7 959.7 514.3 73.2 3.3SG69-8 536 3049 2.0 0.0979 4.8 0.0133 2.9 0.59 84.9 2.4 94.8 4.4 352.7 88.4 84.9 2.4SG69-6 238 1209 2.0 0.1119 19.1 0.0133 1.9 0.10 85.2 1.6 107.7 19.6 638.4 413.0 85.2 1.6SG69-2 5228 3994 24.3 0.1020 6.1 0.0135 4.1 0.68 86.5 3.6 98.6 5.7 401.3 100.0 86.5 3.6SG69-7 328 935 5.4 0.1420 10.8 0.0139 5.6 0.52 88.7 5.0 134.8 13.7 1049.9 187.0 88.7 5.0SG69-1 390 1287 4.5 0.1456 29.9 0.0147 9.3 0.31 94.1 8.7 138.1 38.7 980.4 591.7 94.1 8.7SG69-4 2337 149976 14.9 3.9062 7.8 0.2614 7.7 0.98 1497.2 102.8 1615.0 63.3 1772.1 25.0 1772.1 25.0
SG532A (Pelona Schist; San Gabriel Mountains)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
SG532A-15 347 1331 1.0 0.0798 17.9 0.0112 3.7 0.21 71.7 2.6 78.0 13.4 274.7 403.3 71.7 2.6SG532A-9 333 1229 2.8 0.1326 23.2 0.0164 2.3 0.10 104.9 2.4 126.4 27.6 553.6 511.0 104.9 2.4SG532A-17 42 540 1.0 0.1268 19.1 0.0238 5.2 0.27 151.6 7.8 121.2 21.8 -441.6 485.5 151.6 7.8SG532A-10 608 2366 1.1 0.1716 5.7 0.0239 5.2 0.91 152.2 7.9 160.8 8.5 290.7 52.7 152.2 7.9SG532A-2 404 5010 1.2 0.1819 3.3 0.0251 1.9 0.60 159.5 3.1 169.7 5.1 314.4 59.5 159.5 3.1SG532A-20 678 9985 0.9 0.2183 2.3 0.0323 1.9 0.85 204.8 3.9 200.5 4.1 149.9 27.5 204.8 3.9SG532A-8 58 6750 1.3 2.1369 2.9 0.1973 1.6 0.56 1160.8 17.2 1160.8 20.0 1160.9 47.6 1160.8 17.2SG532A-7 191 15986 1.7 2.9459 2.3 0.2400 1.2 0.54 1386.5 15.2 1393.8 17.2 1404.9 36.6 1404.9 36.6SG532A-14 155 17749 3.6 2.8998 51.8 0.2358 51.8 1.00 1365.0 639.4 1381.9 412.6 1408.0 28.8 1408.0 28.8SG532A-5 134 16381 2.3 2.9822 2.5 0.2419 2.3 0.91 1396.5 28.9 1403.1 19.2 1413.1 19.6 1413.1 19.6SG532A-13 733 74119 2.8 3.0598 2.1 0.2465 1.2 0.57 1420.5 15.0 1422.7 15.7 1426.0 32.1 1426.0 32.1SG532A-6 681 67519 2.3 3.7107 2.7 0.2685 2.3 0.83 1533.2 31.0 1573.7 21.8 1628.4 27.9 1628.4 27.9SG532A-1 1513 105192 2.7 4.2881 2.5 0.3033 2.2 0.89 1707.5 33.2 1691.1 20.6 1670.8 21.3 1670.8 21.3SG532A-4 294 20420 2.7 3.7765 3.5 0.2651 2.9 0.83 1515.8 39.3 1587.8 28.1 1684.7 36.1 1684.7 36.1SG532A-19 845 82855 3.0 4.1483 1.5 0.2894 1.1 0.74 1638.5 15.8 1663.9 12.1 1696.0 18.4 1696.0 18.4SG532A-18 871 49873 4.8 2.7957 3.2 0.1943 2.8 0.87 1144.6 29.2 1354.4 24.1 1703.0 29.7 1703.0 29.7SG532A-11 271 28980 1.7 4.1913 2.4 0.2910 1.6 0.67 1646.7 23.3 1672.3 19.6 1704.6 32.6 1704.6 32.6SG532A-3 235 25756 2.9 4.5286 6.1 0.3118 5.9 0.97 1749.5 89.8 1736.2 50.4 1720.2 27.6 1720.2 27.6SG532A-16 2879 168680 1.8 4.4428 3.6 0.2976 3.5 0.96 1679.2 51.5 1720.4 30.1 1770.9 18.6 1770.9 18.6SG532A-12 445 46631 9.5 4.3156 8.6 0.2728 6.1 0.71 1555.2 84.4 1696.3 70.7 1875.4 108.5 1875.4 108.5
SP10 (Pelona Schist; Sierra Pelona)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
SP10-12 517 3160 1.6 0.0846 3.9 0.0121 2.9 0.75 77.5 2.2 82.5 3.1 228.6 58.7 77.5 2.2SP10-9 99 677 3.0 0.0637 14.0 0.0127 4.6 0.33 81.0 3.7 62.7 8.5 -592.2 358.8 81.0 3.7SP10-11 127 1137 2.9 0.0939 9.7 0.0142 3.7 0.39 91.2 3.4 91.1 8.5 90.4 212.7 91.2 3.4SP10-8 333 2619 6.5 0.1062 6.9 0.0147 2.6 0.38 94.2 2.4 102.5 6.7 300.2 145.0 94.2 2.4SP10-5 1538 5317 3.1 0.1001 3.7 0.0148 1.4 0.37 94.4 1.3 96.9 3.4 158.6 80.0 94.4 1.3SP10-3 3510 16696 3.0 0.0973 3.1 0.0148 2.1 0.69 95.0 2.0 94.3 2.8 78.4 52.4 95.0 2.0SP10-7 239 1402 3.2 0.1252 13.8 0.0151 3.8 0.27 96.3 3.6 119.7 15.5 614.1 286.9 96.3 3.6SP10-4 522 3985 3.4 0.1072 5.2 0.0156 4.0 0.76 99.5 3.9 103.4 5.1 194.6 77.7 99.5 3.9SP10-10 268 2347 2.4 0.1111 4.2 0.0159 1.8 0.44 102.0 1.9 106.9 4.2 219.4 86.2 102.0 1.9SP10-6 896 5843 2.4 0.1164 4.0 0.0160 1.4 0.37 102.4 1.5 111.8 4.2 317.1 83.7 102.4 1.5SP10-15 514 3981 3.4 0.1200 5.6 0.0168 3.5 0.63 107.4 3.8 115.1 6.1 277.8 100.6 107.4 3.8SP10-1 330 2436 2.6 0.1173 5.7 0.0169 3.1 0.54 107.8 3.3 112.6 6.1 215.9 111.6 107.8 3.3SP10-2 375 2535 5.3 0.1362 11.9 0.0169 7.4 0.62 108.0 7.9 129.7 14.4 547.7 203.3 108.0 7.9SP10-13 595 6096 4.3 0.1426 3.2 0.0198 2.6 0.82 126.2 3.3 135.4 4.1 299.4 42.0 126.2 3.3
SP25D (Pelona Schist; Sierra Pelona)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
SP25D-4 597 3904 2.4 0.0907 4.9 0.0129 3.3 0.68 82.6 2.7 88.2 4.1 240.5 81.6 82.6 2.7SP25D-11 1176 3725 1.1 0.1003 9.2 0.0136 3.1 0.34 86.9 2.7 97.1 8.6 355.2 196.6 86.9 2.7SP25D-12 357 2721 1.9 0.1023 6.7 0.0137 4.4 0.65 87.5 3.8 98.9 6.3 383.9 114.1 87.5 3.8SP25D-8 1354 9201 2.4 0.0916 3.0 0.0141 2.8 0.93 90.1 2.5 89.0 2.6 58.3 25.8 90.1 2.5SP25D-15 919 7661 2.7 0.0996 3.4 0.0142 1.7 0.50 90.8 1.5 96.4 3.2 236.8 68.5 90.8 1.5SP25D-6 1398 12428 2.2 0.0956 2.0 0.0146 1.5 0.77 93.5 1.4 92.7 1.7 73.6 29.5 93.5 1.4SP25D-13 1335 2978 1.4 0.1157 11.7 0.0148 4.1 0.35 94.9 3.9 111.1 12.3 475.7 242.3 94.9 3.9SP25D-1 1101 3564 2.1 0.1159 12.7 0.0152 5.2 0.41 97.3 5.1 111.4 13.4 423.8 258.7 97.3 5.1SP25D-14 1475 10826 1.8 0.1030 6.6 0.0155 6.3 0.94 99.4 6.2 99.5 6.3 104.1 52.0 99.4 6.2SP25D-2 1180 790 0.9 0.1755 19.4 0.0159 3.7 0.19 101.8 3.7 164.2 29.5 1196.1 379.7 101.8 3.7SP25D-9 1754 8871 5.9 0.1317 12.4 0.0167 3.7 0.30 106.6 3.9 125.7 14.7 503.0 262.2 106.6 3.9SP25D-5 221 1731 3.0 0.1664 13.3 0.0194 5.8 0.43 124.1 7.1 156.3 19.2 677.1 256.2 124.1 7.1SP25D-10 216 2853 1.2 0.2167 2.8 0.0285 2.2 0.77 181.3 3.9 199.2 5.1 416.3 40.6 181.3 3.9SP25D-7 78 6399 1.0 1.7905 4.0 0.1762 3.3 0.85 1045.9 32.3 1042.0 25.8 1033.7 42.7 1045.9 32.3
SP60 (Pelona Schist; Sierra Pelona)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
SP60-05 405 2111 1.3 0.0764 7.6 0.0130 2.8 0.37 83.3 2.3 74.8 5.5 -190.5 175.9 83.3 2.3SP60-09 366 3881 3.5 0.0761 5.1 0.0132 3.6 0.71 84.5 3.0 74.5 3.7 -236.1 90.1 84.5 3.0SP60-04 834 6447 1.9 0.0865 3.6 0.0133 2.6 0.73 84.9 2.2 84.3 2.9 67.0 58.1 84.9 2.2SP60-13 220 1885 1.3 0.0679 13.3 0.0136 4.8 0.36 87.0 4.1 66.7 8.6 -611.3 340.9 87.0 4.1SP60-22A 449 3427 1.0 0.0845 4.4 0.0139 2.5 0.57 88.9 2.2 82.4 3.5 -102.0 88.5 88.9 2.2SP60-10 262 2078 2.3 0.0714 9.8 0.0140 3.5 0.36 89.6 3.1 70.0 6.6 -554.7 245.9 89.6 3.1SP60-17 223 952 1.3 0.0905 15.6 0.0140 4.4 0.28 89.9 3.9 88.0 13.2 36.4 360.9 89.9 3.9SP60-18 482 4153 2.9 0.0973 9.1 0.0142 3.3 0.37 91.1 3.0 94.3 8.2 176.1 197.2 91.1 3.0SP60-20 1830 11142 1.7 0.0910 1.9 0.0143 1.6 0.84 91.6 1.5 88.4 1.6 3.5 25.7 91.6 1.5SP60-21 262 1984 1.6 0.0691 10.6 0.0143 5.9 0.56 91.7 5.4 67.8 7.0 -710.2 244.6 91.7 5.4SP60-14 485 3313 2.2 0.0884 6.6 0.0146 3.8 0.58 93.3 3.6 86.0 5.4 -112.3 131.8 93.3 3.6SP60-07 605 5267 1.5 0.0928 3.4 0.0147 1.8 0.52 94.3 1.7 90.1 2.9 -17.6 70.5 94.3 1.7SP60-08 702 8668 1.8 0.0990 3.2 0.0151 2.3 0.70 96.5 2.2 95.8 3.0 80.4 55.3 96.5 2.2SP60-23 355 2683 1.9 0.0895 3.8 0.0156 2.2 0.58 99.9 2.2 87.1 3.2 -251.2 79.0 99.9 2.2SP60-12 312 3395 1.7 0.0943 4.8 0.0157 2.6 0.54 100.4 2.6 91.5 4.2 -133.3 100.3 100.4 2.6SP60-02 861 4216 3.2 0.1099 4.6 0.0157 1.0 0.22 100.5 1.0 105.9 4.6 227.7 103.1 100.5 1.0SP60-25 666 12208 1.9 0.1027 5.5 0.0158 3.9 0.71 101.0 3.9 99.3 5.2 58.8 92.6 101.0 3.9SP60-19 2023 2639 1.8 0.1135 7.7 0.0158 5.5 0.72 101.2 5.5 109.2 7.9 287.7 121.7 101.2 5.5SP60-15 559 3186 1.4 0.1127 6.5 0.0168 4.6 0.72 107.7 5.0 108.5 6.7 125.4 105.9 107.7 5.0SP60-16 1394 8806 2.9 0.1055 3.6 0.0172 3.1 0.85 109.8 3.3 101.9 3.5 -80.5 47.1 109.8 3.3SP60-24 184 720 2.2 0.1605 31.8 0.0174 5.8 0.18 111.0 6.4 151.2 44.6 838.3 665.6 111.0 6.4SP60-01 359 3756 1.3 0.1146 5.1 0.0192 2.4 0.47 122.8 3.0 110.2 5.4 -154.6 112.6 122.8 3.0SP60-11A 234 2559 1.2 0.1286 4.6 0.0206 2.2 0.47 131.5 2.8 122.8 5.3 -43.1 98.1 131.5 2.8SP60-15A 288 4954 2.9 0.1293 6.6 0.0214 2.2 0.33 136.5 2.9 123.5 7.6 -119.2 152.8 136.5 2.9SP60-22 237 19232 2.5 0.6595 5.6 0.0678 5.5 0.97 422.7 22.3 514.3 22.7 945.6 28.8 945.6 28.8
SP70 (Pelona Schist; Sierra Pelona)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
SP70-12 147 1226 1.2 0.0658 13.1 0.0145 4.6 0.35 92.8 4.3 64.7 8.2 -882.4 354.6 92.8 4.3SP70-08 376 6539 3.5 0.0900 4.9 0.0145 2.1 0.42 92.9 1.9 87.5 4.1 -56.4 109.1 92.9 1.9SP70-11 268 3059 1.9 0.0696 8.5 0.0146 3.9 0.46 93.5 3.6 68.3 5.6 -743.3 212.5 93.5 3.6SP70-13 731 7548 1.0 0.1015 6.2 0.0151 5.2 0.84 96.4 5.0 98.2 5.8 141.0 80.2 96.4 5.0SP70-18A 292 3743 1.4 0.0985 6.9 0.0151 3.0 0.43 96.6 2.8 95.4 6.2 65.8 147.4 96.6 2.8SP70-19 816 4424 2.0 0.1102 6.5 0.0153 2.3 0.35 98.0 2.2 106.2 6.5 294.5 138.5 98.0 2.2SP70-10 560 4878 1.8 0.1040 3.6 0.0157 2.5 0.68 100.5 2.5 100.4 3.5 98.0 62.5 100.5 2.5SP70-20 564 775 1.7 0.1430 8.6 0.0158 2.5 0.29 100.7 2.5 135.7 11.0 801.1 173.4 100.7 2.5SP70-02 399 4898 1.5 0.0996 7.5 0.0159 5.7 0.76 101.5 5.7 96.4 6.9 -28.7 117.8 101.5 5.7SP70-05 788 5011 1.5 0.1171 6.9 0.0161 2.1 0.31 103.1 2.2 112.4 7.3 316.0 148.6 103.1 2.2SP70-17B 747 7063 2.4 0.1107 6.8 0.0161 4.7 0.69 103.1 4.8 106.6 6.9 186.0 114.7 103.1 4.8SP70-16A 463 7385 1.2 0.1075 9.6 0.0162 7.6 0.79 103.3 7.8 103.7 9.4 112.6 138.8 103.3 7.8SP70-17A 854 8520 1.9 0.1111 6.6 0.0162 5.9 0.89 103.7 6.1 106.9 6.7 179.7 71.3 103.7 6.1SP70-14 755 7835 1.4 0.1110 8.1 0.0163 6.3 0.78 104.1 6.5 106.9 8.2 170.0 116.9 104.1 6.5SP70-06 472 3832 2.1 0.1160 6.2 0.0165 3.4 0.54 105.5 3.5 111.5 6.6 240.1 121.2 105.5 3.5SP70-04 326 343 1.2 0.2227 10.8 0.0165 6.0 0.55 105.8 6.3 204.2 20.0 1579.5 169.5 105.8 6.3SP70-07 424 4554 1.5 0.1046 5.0 0.0168 1.7 0.33 107.2 1.8 101.0 4.8 -42.7 115.6 107.2 1.8SP70-04A 885 6286 2.1 0.1153 6.9 0.0169 6.1 0.88 108.0 6.5 110.8 7.3 170.7 77.8 108.0 6.5SP70-17 418 5736 1.5 0.1020 8.0 0.0169 4.6 0.58 108.3 5.0 98.7 7.5 -129.4 161.1 108.3 5.0SP70-09 271 2969 1.9 0.0859 9.3 0.0174 2.3 0.25 111.0 2.6 83.7 7.5 -640.3 246.9 111.0 2.6SP70-03 465 1948 2.9 0.0984 12.6 0.0178 5.1 0.40 113.8 5.7 95.3 11.5 -344.8 298.9 113.8 5.7SP70-16B 173 2106 1.5 0.1037 12.7 0.0185 1.9 0.15 118.2 2.2 100.2 12.1 -308.6 322.7 118.2 2.2
SP71 (Pelona Schist; Sierra Pelona)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
SP71-19 587 2076 1.0 0.0881 6.1 0.0133 1.7 0.28 85.0 1.4 85.7 5.0 105.6 139.4 85.0 1.4SP71-20 440 3248 1.8 0.0899 7.2 0.0134 3.4 0.47 85.6 2.9 87.4 6.0 137.3 149.6 85.6 2.9SP71-21 454 2366 1.8 0.0805 4.5 0.0135 2.2 0.49 86.4 1.9 78.6 3.4 -152.9 98.4 86.4 1.9SP71-14 270 1101 1.5 0.0594 19.6 0.0140 3.9 0.20 89.6 3.5 58.6 11.2 -1080.2 583.8 89.6 3.5SP71-06 714 4944 5.1 0.0891 4.2 0.0141 3.1 0.74 90.1 2.8 86.7 3.5 -6.8 68.2 90.1 2.8SP71-25 687 4594 1.6 0.0918 4.2 0.0143 2.4 0.56 91.8 2.1 89.1 3.6 18.7 83.1 91.8 2.1SP71-24B 313 2117 2.1 0.0890 8.4 0.0146 3.8 0.45 93.2 3.5 86.6 7.0 -91.8 184.2 93.2 3.5SP71-10 1829 8875 1.4 0.1000 4.8 0.0154 2.3 0.48 98.4 2.2 96.8 4.4 58.2 99.5 98.4 2.2SP71-07 777 6123 2.7 0.1026 4.1 0.0154 2.3 0.57 98.5 2.3 99.2 3.8 114.6 78.6 98.5 2.3SP71-16 563 5148 1.9 0.1011 5.7 0.0154 2.6 0.46 98.5 2.6 97.8 5.3 79.3 119.9 98.5 2.6SP71-12 880 5189 1.7 0.1054 3.6 0.0154 1.5 0.41 98.7 1.4 101.7 3.5 174.2 75.7 98.7 1.4SP71-02 331 2824 1.6 0.1029 4.8 0.0155 2.0 0.43 99.1 2.0 99.5 4.6 108.2 103.0 99.1 2.0SP71-11 764 3080 3.3 0.0908 11.1 0.0157 6.4 0.57 100.6 6.3 88.2 9.4 -236.8 231.2 100.6 6.3SP71-24A 629 2974 1.5 0.1331 15.1 0.0158 4.1 0.27 100.9 4.1 126.9 18.0 646.4 314.1 100.9 4.1SP71-23 418 1647 2.7 0.1221 9.3 0.0158 6.5 0.70 101.1 6.5 117.0 10.3 454.1 148.4 101.1 6.5SP71-15 256 2069 2.1 0.0925 9.2 0.0160 3.4 0.37 102.4 3.5 89.8 7.9 -232.8 216.1 102.4 3.5SP71-05 543 8228 1.7 0.1034 4.9 0.0161 3.9 0.79 103.3 3.9 99.9 4.7 21.2 72.7 103.3 3.9SP71-03 852 3779 1.6 0.1185 5.5 0.0164 1.8 0.33 104.8 1.9 113.7 5.9 303.3 117.6 104.8 1.9SP71-09 215 1853 1.6 0.0794 9.6 0.0167 2.5 0.26 106.9 2.7 77.5 7.2 -755.2 261.4 106.9 2.7SP71-01 173 930 1.8 0.0801 14.6 0.0167 4.8 0.33 107.1 5.1 78.3 11.0 -732.1 385.9 107.1 5.1SP71-04A 285 2730 3.4 0.0938 7.9 0.0170 5.1 0.64 108.6 5.5 91.1 6.8 -346.3 155.0 108.6 5.5SP71-08 185 2984 1.8 0.1588 10.0 0.0271 6.3 0.63 172.7 10.7 149.6 13.9 -201.5 196.0 172.7 10.7SP71-11A 803 15063 2.3 0.5873 8.1 0.0745 7.5 0.92 463.2 33.6 469.1 30.6 498.1 68.6 463.2 33.6SP71-17 245 14644 1.3 1.6859 3.1 0.1615 2.4 0.77 965.0 21.8 1003.2 20.0 1087.7 39.8 1087.7 39.8SP71-04 87 20893 4.1 2.6733 9.1 0.2266 8.8 0.97 1316.9 105.2 1321.1 67.0 1328.0 39.2 1328.0 39.2SP71-13 498 72605 3.4 2.9883 3.0 0.2357 2.4 0.79 1364.1 29.2 1404.6 23.0 1466.7 35.5 1466.7 35.5
SP81 (Pelona Schist; Sierra Pelona)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
SP81-03A 174 827 0.8 0.0394 30.6 0.0117 4.6 0.15 75.0 3.4 39.2 11.8 -1844.8 1112.8 75.0 3.4SP81-01C 641 2356 1.1 0.0784 7.3 0.0120 2.0 0.27 76.9 1.5 76.7 5.4 68.4 166.2 76.9 1.5SP81-19 543 1738 1.6 0.0776 5.9 0.0121 3.8 0.64 77.6 2.9 75.9 4.3 21.7 108.8 77.6 2.9SP81-20B 759 3476 1.2 0.0748 3.7 0.0122 2.3 0.61 78.3 1.8 73.2 2.6 -89.6 72.4 78.3 1.8SP81-11A 991 5027 1.4 0.0778 4.9 0.0124 3.5 0.71 79.3 2.8 76.1 3.6 -22.8 84.4 79.3 2.8SP81-24 235 1119 1.1 0.0422 14.1 0.0126 5.0 0.36 80.8 4.0 41.9 5.8 -1865.8 478.3 80.8 4.0SP81-02 311 1378 1.3 0.0684 7.5 0.0127 2.5 0.33 81.1 2.0 67.2 4.9 -401.4 184.7 81.1 2.0SP81-01B 1250 8481 1.0 0.0836 4.3 0.0130 3.4 0.79 83.1 2.8 81.5 3.3 34.5 63.0 83.1 2.8SP81-14A 177 965 0.7 0.0394 16.6 0.0132 3.8 0.23 84.7 3.2 39.2 6.4 -2316.2 659.9 84.7 3.2SP81-10 362 2737 2.4 0.0731 7.6 0.0133 3.2 0.41 85.1 2.7 71.6 5.3 -355.8 179.0 85.1 2.7SP81-23 930 5441 3.3 0.0939 6.4 0.0145 6.1 0.94 92.7 5.6 91.2 5.6 51.5 52.1 92.7 5.6SP81-11 685 3403 3.4 0.0904 6.1 0.0145 4.5 0.75 92.8 4.2 87.9 5.1 -42.9 97.9 92.8 4.2SP81-04 863 4186 1.4 0.1088 6.1 0.0154 3.8 0.62 98.7 3.7 104.8 6.1 247.1 111.2 98.7 3.7SP81-25 578 3553 2.3 0.0989 11.0 0.0156 6.6 0.60 100.0 6.6 95.8 10.1 -7.9 213.7 100.0 6.6SP81-15 630 3915 2.7 0.1049 7.1 0.0159 2.5 0.36 101.6 2.6 101.3 6.9 94.3 158.2 101.6 2.6SP81-06 481 3498 2.0 0.0977 7.6 0.0162 2.9 0.38 103.7 2.9 94.7 6.8 -126.3 173.3 103.7 2.9SP81-12 202 2636 1.5 0.0622 19.1 0.0167 1.6 0.08 106.5 1.7 61.3 11.4 -1485.6 635.1 106.5 1.7SP81-09B 136 993 1.3 0.0478 15.3 0.0167 5.4 0.35 106.8 5.7 47.5 7.1 -2473.7 604.5 106.8 5.7SP81-22 547 2775 1.9 0.1095 6.3 0.0172 3.2 0.51 109.8 3.5 105.5 6.3 9.5 130.2 109.8 3.5SP81-14 89 601 1.2 0.0804 17.2 0.0189 6.0 0.35 120.6 7.2 78.5 13.0 -1070.8 487.6 120.6 7.2SP81-21 199 1923 1.6 0.1221 9.9 0.0205 3.3 0.33 131.1 4.3 116.9 11.0 -162.0 233.1 131.1 4.3SP81-17A 112 961 0.8 0.0857 21.3 0.0255 4.5 0.21 162.4 7.2 83.5 17.1 -1850.5 758.9 162.4 7.2SP81-16 401 5954 2.3 0.2652 2.7 0.0417 2.1 0.79 263.4 5.5 238.9 5.8 4.1 40.5 263.4 5.5SP81-07 304 15064 1.5 0.3153 3.0 0.0439 1.6 0.54 277.0 4.4 278.3 7.4 289.3 58.2 277.0 4.4SP81-13 317 34775 1.1 2.9032 3.1 0.2407 2.6 0.84 1390.4 32.5 1382.7 23.5 1371.0 33.0 1371.0 33.0SP81-08 1168 110966 28.0 3.6722 2.9 0.2776 2.1 0.73 1579.3 30.1 1565.3 23.5 1546.5 38.0 1546.5 38.0SP81-05 913 80665 10.8 3.4649 5.3 0.2539 2.9 0.56 1458.5 38.2 1519.3 41.5 1604.9 81.5 1604.9 81.5SP81-18 387 19507 1.6 4.8627 3.1 0.3268 2.1 0.69 1823.1 34.1 1795.8 26.2 1764.3 41.0 1764.3 41.0
YN17 (Orocopia Schist; Picacho Area)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
YN17-3 327 2081 2.7 0.0783 5.7 0.0116 2.3 0.40 74.3 1.7 76.6 4.2 148.8 122.9 74.3 1.7YN17-2 296 2146 2.8 0.0788 4.5 0.0117 3.6 0.80 75.3 2.7 77.0 3.3 131.5 63.8 75.3 2.7YN17-12 404 2526 1.0 0.0877 5.1 0.0129 3.3 0.65 82.5 2.7 85.3 4.2 165.7 90.7 82.5 2.7YN17-15 212 1149 2.1 0.1025 10.7 0.0133 8.4 0.79 85.1 7.1 99.1 10.1 450.8 146.4 85.1 7.1YN17-11 313 1916 0.9 0.0896 5.4 0.0133 2.9 0.55 85.2 2.5 87.1 4.5 141.5 105.3 85.2 2.5YN17-5 417 2190 2.2 0.0995 3.4 0.0136 2.0 0.59 86.9 1.8 96.3 3.1 334.4 62.6 86.9 1.8YN17-4 270 1540 1.7 0.1010 7.9 0.0140 5.0 0.63 89.7 4.4 97.7 7.4 299.4 140.0 89.7 4.4YN17-1 954 5446 0.8 0.0973 4.6 0.0141 4.4 0.96 90.3 4.0 94.2 4.2 195.9 29.5 90.3 4.0YN17-13 297 4052 1.3 0.2373 8.2 0.0324 7.9 0.97 205.3 15.9 216.2 15.9 336.6 46.7 205.3 15.9YN17-6 267 5822 2.5 0.2926 5.0 0.0395 4.1 0.82 249.8 10.0 260.6 11.5 358.6 65.3 249.8 10.0YN17-10 216 28674 2.1 4.2510 3.5 0.2989 3.3 0.96 1686.1 49.1 1683.9 28.4 1681.2 18.5 1681.2 18.5YN17-7 183 10850 1.8 4.4074 1.6 0.3069 1.3 0.78 1725.3 19.3 1713.7 13.6 1699.6 19.1 1699.6 19.1YN17-14 957 99947 2.8 4.2939 2.9 0.2972 2.7 0.94 1677.2 39.7 1692.2 23.6 1710.8 18.4 1710.8 18.4YN17-9 173 27373 2.1 4.7308 3.1 0.3165 2.9 0.95 1772.7 45.0 1772.7 25.7 1772.7 18.3 1772.7 18.3YN17-8 208 4774 2.5 5.3054 11.7 0.3120 3.3 0.28 1750.7 50.1 1869.7 99.9 2004.7 199.2 2004.7 199.2
Zircon U-Pb Data Tables
Forearc Sedimentary Units Analyzed with UCLA Ion Microprobe
Note that results for some samples are presented in several tables (labeled as “Part 1,” “Part 2,” etc.). Each table represents a different calibration curve, either because the standardization changed during the course of a single analysis session or because analyses were obtained during several different sessions.
03-01 (Cambria slab; Cambria) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
82 ± 2 80 ± 10 96.0 57.2 - 308 103 8.25 (208Pb) 02-06 86 ± 2 79 ± 8 98.3 74.9 - 260 110 8.23 (208Pb) 02-13 88 ± 2 88 ± 9 97.9 72.9 - 661 334 8.40 (208Pb) 02-09
109 ± 1 127 ± 3 99.5 92.9 - 1462 29 8.32 (208Pb) 02-12 115 ± 3 108 ± 33 95.4 52.9 - 155 70 8.28 (208Pb) 02-07
124 ± 10 115 ± 104 82.1 19.3 - 32 33 8.23 (208Pb) 02-08 132 ± 1 134 ± 8 99.3 89.5 - 852 479 8.04 (208Pb) 02-10 140 ± 5 140 ± 21 97.4 68.3 - 178 49 8.06 (208Pb) 02-15 143 ± 2 144 ± 9 99.1 86.4 - 462 80 8.35 (208Pb) 02-11 146 ± 6 144 ± 45 92.6 42.0 - 84 33 8.51 (208Pb) 02-05 149 ± 6 169 ± 24 96.5 64.8 - 97 39 8.10 (208Pb) 02-01 204 ± 6 203 ± 47 96.3 60.7 - 65 20 8.24 (208Pb) 02-14
1363 ± 18 1377 ± 14 99.9 98.8 1400 ± 19 410 67 8.12 (204Pb) 02-03 1472 ± 18 1513 ± 12 99.9 99.0 1570 ± 11 754 89 8.34 (204Pb) 02-04 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.894±0.010 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/17/2004: RSFPb/U = 1.749 x UO+/U+ - 8.989 for UO+/U+ values in the range 7.68< UO+/U+
<8.28. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.8%.
03-03 (Cambria slab; Cambria) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
87 ± 1 87 ± 6 99.0 85.5 - 771 179 8.21 (208Pb) 04-09 87 ± 3 79 ± 39 92.5 38.8 - 112 48 8.12 (208Pb) 04-08 88 ± 1 89 ± 13 98.2 76.0 - 330 173 8.30 (208Pb) 04-17 90 ± 1 81 ± 13 97.2 63.8 - 425 174 8.24 (208Pb) 04-02
104 ± 4 114 ± 18 98.0 75.9 - 188 184 8.04 (208Pb) 04-01 108 ± 2 97 ± 6 97.6 67.4 - 852 65 8.20 (208Pb) 04-03 119 ± 4 98 ± 58 94.0 42.4 - 127 17 8.25 (208Pb) 04-10 123 ± 4 145 ± 40 93.5 49.8 - 91 27 8.16 (208Pb) 04-06 123 ± 3 129 ± 14 98.5 80.0 - 213 91 8.09 (208Pb) 04-15 156 ± 7 148 ± 104 91.4 37.0 - 35 20 8.02 (208Pb) 04-12 165 ± 2 153 ± 8 99.1 86.3 - 341 152 8.13 (208Pb) 04-13 188 ± 5 175 ± 36 95.8 55.6 - 128 40 8.36 (208Pb) 04-05 236 ± 6 217 ± 19 98.9 83.1 - 187 93 8.19 (204Pb) 04-11
804 ± 14 971 ± 11 99.8 98.2 1372 ± 30 233 41 8.09 (204Pb) 04-18 1351 ± 18 1356 ± 13 99.9 98.9 1364 ± 22 213 40 8.16 (204Pb) 04-16 1398 ± 26 1394 ± 18 99.9 98.8 1389 ± 25 391 236 8.22 (204Pb) 04-07 1406 ± 17 1390 ± 12 99.8 98.3 1365 ± 22 317 53 8.26 (204Pb) 04-04 1580 ± 23 1592 ± 14 100.0 99.6 1608 ± 11 623 194 8.08 (204Pb) 04-14 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.894±0.010 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/17/2004: RSFPb/U = 1.749 x UO+/U+ - 8.989 for UO+/U+ values in the range 7.68< UO+/U+
<8.28. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.8%.
03-04 (Carmelo Formation; Point Lobos) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
83 ± 1 87 ± 6 98.8 83.4 - 330 193 8.08 (208Pb) 06-08 83 ± 1 88 ± 6 99.7 94.6 - 353 234 8.09 (208Pb) 06-01 85 ± 2 81 ± 10 98.3 76.0 - 457 221 8.28 (208Pb) 06-13 86 ± 2 81 ± 12 98.5 77.6 - 313 224 8.19 (208Pb) 06-05 89 ± 2 84 ± 6 99.1 86.0 - 352 148 8.09 (208Pb) 06-10 91 ± 1 73 ± 8 97.3 62.2 - 236 85 8.03 (208Pb) 06-04 92 ± 1 90 ± 5 99.5 92.0 - 906 306 8.10 (208Pb) 06-02 93 ± 1 88 ± 13 98.3 76.3 - 451 46 8.20 (208Pb) 06-16 96 ± 2 102 ± 26 96.9 65.7 - 263 219 8.18 (208Pb) 06-15 98 ± 2 96 ± 26 96.9 63.2 - 119 78 8.71 (208Pb) 06-06
100 ± 2 88 ± 13 97.2 63.7 - 181 80 8.15 (208Pb) 06-12 100 ± 2 105 ± 9 99.6 93.3 - 368 200 8.20 (208Pb) 06-07 106 ± 3 95 ± 12 97.9 71.0 - 343 128 8.14 (208Pb) 06-14 255 ± 7 234 ± 45 98.1 74.4 - 72 44 8.17 (204Pb) 06-11 263 ± 6 263 ± 16 99.3 90.2 - 218 108 8.12 (204Pb) 06-03 267 ± 4 283 ± 10 99.6 93.8 - 182 46 8.08 (204Pb) 06-09
†Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.894±0.010 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 03/17/2004: RSFPb/U = 1.749 x UO+/U+ - 8.989 for UO+/U+ values in the range 7.68< UO+/U+
<8.28. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.8%.
99-65 – Part 1 (Cambria slab; Cambria) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
89 ± 2 75 ± 9 98.1 71.4 - 369 - 8.31 (204Pb) 02-02 100 ± 5 93 ± 12 97.8 70.0 - 279 - 8.49 (204Pb) 02-08 100 ± 2 95 ± 12 97.4 66.7 - 435 - 8.28 (204Pb) 02-09 101 ± 3 106 ± 12 98.3 78.2 - 225 - 8.22 (204Pb) 02-07 104 ± 5 104 ± 18 97.6 69.9 - 383 - 8.53 (204Pb) 02-04 104 ± 2 106 ± 11 97.6 70.6 - 485 - 8.29 (204Pb) 02-05 112 ± 4 112 ± 6 98.8 83.0 - 1028 - 8.16 (204Pb) 02-11 120 ± 4 143 ± 15 97.3 71.7 - 416 - 8.37 (204Pb) 02-03 162 ± 4 161 ± 13 98.5 79.1 - 552 - 8.25 (204Pb) 02-10 166 ± 5 163 ± 15 98.3 76.8 - 425 - 8.18 (204Pb) 02-12 167 ± 4 162 ± 11 98.6 80.1 - 408 - 8.30 (204Pb) 02-01
†Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.500±0.020 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 8/24/1999: RSFPb/U = 2.144 x UO+/U+ - 12.866 for UO+/U+ values in the range 8.05< UO+/U+
<8.49. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 4.1%.
99-65 – Part 2 (Cambria slab; Cambria) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
93 ± 3 123 ± 15 98.8 86.3 - 120 - 8.42 (204Pb) 04-13 99 ± 1 102 ± 7 98.9 84.0 - 651 - 8.37 (204Pb) 03-02
117 ± 2 116 ± 11 98.7 81.3 - 243 - 8.20 (204Pb) 02-17 123 ± 4 136 ± 23 96.5 64.0 - 333 - 8.11 (204Pb) 02-20 153 ± 8 213 ± 55 94.4 58.7 - 40 - 8.30 (204Pb) 02-22 153 ± 2 153 ± 6 99.3 89.2 - 1071 - 8.20 (204Pb) 02-21 158 ± 4 160 ± 9 99.3 89.6 - 359 - 8.18 (204Pb) 02-13
162 ± 11 185 ± 56 94.5 54.1 - 73 - 8.20 (204Pb) 02-19 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.500±0.020 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition
of common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 8/24/1999: RSFPb/U = 2.455 x UO+/U+ - 15.156 for UO+/U+ values in the range 8.03< UO+/U+
<8.44. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.9%.
99-65 – Part 3 (Cambria slab; Cambria) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
81 ± 1 76 ± 6 98.3 75.5 - 796 - 8.49 (204Pb) 03-07 96 ± 2 103 ± 14 98.4 79.1 - 448 - 8.19 (204Pb) 03-06
103 ± 2 127 ± 8 100.0 101.0 - 404 - 8.14 (204Pb) 03-05 118 ± 3 127 ± 11 99.1 86.8 - 524 - 8.00 (204Pb) 03-04
†Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.500±0.020 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 8/25/1999: RSFPb/U = 2.152 x UO+/U+ - 13.203 for UO+/U+ values in the range 7.42< UO+/U+
<8.57. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 3.6%.
99-65 – Part 4 (Cambria slab; Cambria) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
106 ± 2 117 ± 5 100.0 101.0 - 752 - 8.51 (204Pb) 04-16 106 ± 2 114 ± 4 98.3 75.7 - 854 - 8.60 (204Pb) 03-19 106 ± 5 123 ± 24 94.1 51.3 - 85 - 7.99 (204Pb) 04-10 110 ± 3 113 ± 31 98.4 78.5 - 391 - 8.10 (204Pb) 03-10 120 ± 2 128 ± 5 98.8 85.1 - 805 - 8.77 (204Pb) 04-11 121 ± 3 151 ± 12 39.6 -36.3 - 235 - 7.99 (204Pb) 04-03 133 ± 7 151 ± 49 99.4 91.7 - 96 - 8.12 (204Pb) 03-08 139 ± 3 149 ± 6 99.5 92.8 - 621 - 8.17 (204Pb) 04-08 147 ± 7 208 ± 63 96.6 62.5 - 91 - 8.00 (204Pb) 03-11 154 ± 4 162 ± 15 99.9 98.6 - 185 - 8.28 (204Pb) 04-15 155 ± 4 177 ± 24 94.7 59.9 - 347 - 7.82 (204Pb) 03-13 158 ± 3 182 ± 9 99.7 95.5 - 314 - 8.37 (204Pb) 04-12 173 ± 6 169 ± 22 99.9 97.9 - 176 - 8.58 (204Pb) 02-06
†Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.500±0.020 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 8/26/1999: RSFPb/U = 2.152 x UO+/U+ - 13.203 for UO+/U+ values in the range 7.42< UO+/U+
<8.57. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 3.6%.
99-66A (Cambria slab; Cambria) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
74 ± 5 80 ± 5 100.0 104.0 - 496 - 8.62 (204Pb) 07-08 80 ± 5 74 ± 11 98.0 71.4 - 247 - 8.33 (204Pb) 07-11 85 ± 5 99 ± 12 98.8 84.3 - 285 - 8.16 (204Pb) 06-02 85 ± 5 88 ± 5 99.7 94.6 - 687 - 8.50 (204Pb) 08-11 87 ± 4 90 ± 7 99.4 90.4 - 523 - 8.48 (204Pb) 06-04 88 ± 5 92 ± 11 98.2 76.6 - 287 - 8.34 (204Pb) 06-05 88 ± 5 100 ± 8 99.7 95.9 - 436 - 8.41 (204Pb) 09-09 90 ± 5 100 ± 11 99.2 88.7 - 333 - 8.39 (204Pb) 09-02 90 ± 3 77 ± 12 98.8 79.8 - 755 - 8.27 (204Pb) 08-09 94 ± 3 94 ± 7 99.3 89.6 - 566 - 8.25 (204Pb) 06-14 97 ± 4 102 ± 10 99.2 87.9 - 405 - 8.25 (204Pb) 08-13 97 ± 4 102 ± 7 99.2 88.3 - 391 - 8.23 (204Pb) 09-12 98 ± 5 102 ± 20 97.9 73.5 - 102 - 8.44 (204Pb) 06-03 98 ± 4 89 ± 9 98.4 75.4 - 276 - 8.21 (204Pb) 06-13 99 ± 7 101 ± 8 99.6 93.3 - 761 - 8.69 (204Pb) 09-03 99 ± 3 96 ± 6 99.2 87.7 - 848 - 8.22 (204Pb) 07-04
100 ± 4 102 ± 6 99.5 91.4 - 629 - 8.40 (204Pb) 07-10 100 ± 5 107 ± 12 98.9 85.2 - 258 - 8.47 (204Pb) 07-14 100 ± 4 105 ± 5 99.5 92.6 - 749 - 8.38 (204Pb) 08-04 100 ± 4 105 ± 7 99.5 91.9 - 544 - 8.34 (204Pb) 09-06 103 ± 3 104 ± 11 98.6 80.3 - 320 - 8.22 (204Pb) 08-07 104 ± 4 119 ± 7 100.0 101.0 - 458 - 8.06 (204Pb) 08-15 105 ± 6 112 ± 11 99.1 86.8 - 280 - 8.09 (204Pb) 07-06 105 ± 4 120 ± 6 99.5 92.7 - 666 - 8.21 (204Pb) 09-11 107 ± 5 95 ± 11 97.9 70.7 - 316 - 8.27 (204Pb) 09-01 109 ± 5 103 ± 9 98.7 80.4 - 404 - 8.06 (204Pb) 06-07 113 ± 3 197 ± 6 99.8 98.2 1382 ± 24 2318 - 8.30 (204Pb) 09-07 118 ± 7 111 ± 25 97.0 63.7 - 202 - 7.92 (204Pb) 07-02 120 ± 7 131 ± 13 99.4 90.9 - 386 - 7.95 (204Pb) 06-08 121 ± 5 122 ± 8 99.6 94.0 - 1066 - 8.14 (204Pb) 06-09 174 ± 6 185 ± 8 99.9 98.3 - 524 - 8.26 (204Pb) 08-05 174 ± 8 177 ± 13 99.2 88.6 - 241 - 8.42 (204Pb) 08-03
†Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.871±0.014 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/18/2004: RSFPb/U = 2.310x UO+/U+ - 12.904 for UO+/U+ values in the range 6.97< UO+/U+
<8.05. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 7.0%.
99-68 (Atascadero Formation; Atascadero) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
80 ± 4 97 ± 24 98.3 79.8 - 106 80 9.60 (208Pb) 12-14 81 ± 3 84 ± 8 99.4 91.0 - 473 179 9.38 (208Pb) 12-15 84 ± 3 83 ± 7 99.0 85.0 - 314 119 9.37 (208Pb) 12-12 91 ± 4 96 ± 16 98.6 81.1 - 110 46 9.56 (208Pb) 12-10 94 ± 3 95 ± 9 98.4 77.5 - 272 145 9.43 (208Pb) 12-11 95 ± 5 105 ± 14 99.8 97.5 - 178 100 9.32 (208Pb) 12-16 97 ± 4 106 ± 10 99.5 92.9 - 238 140 9.35 (208Pb) 12-04 98 ± 5 112 ± 13 99.9 98.3 - 116 68 9.28 (208Pb) 12-03
103 ± 7 105 ± 19 98.5 79.1 - 107 55 9.48 (208Pb) 12-13 107 ± 6 103 ± 7 99.7 94.6 - 467 210 8.77 (204Pb) 12-06 120 ± 6 124 ± 17 99.0 86.0 - 80 23 9.44 (208Pb) 12-02
147 ± 10 136 ± 41 96.6 60.8 - 69 22 8.93 (204Pb) 12-08 151 ± 7 157 ± 9 99.7 94.9 - 429 341 9.55 (204Pb) 12-07
1414 ± 53 1526 ± 34 99.9 99.0 1686 ± 12 407 50 8.94 (204Pb) 12-05 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.885±0.018 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 12/21/2001: RSFPb/U = 3.854 x UO+/U+ - 28.787 for UO+/U+ values in the range 8.46< UO+/U+
<9.33. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 6.7%.
BB1 – Part 1 (Butano Formation; Ben Lomond Mountain) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
87 ± 7 98 ± 24 99.3 90.2 - 128 150 9.05 (208Pb) 07-05 94 ± 4 90 ± 6 99.2 87.7 - 517 123 8.95 (208Pb) 07-07 96 ± 5 101 ± 13 99.4 91.4 - 419 456 8.84 (208Pb) 07-18 96 ± 4 92 ± 10 98.2 75.0 - 469 165 8.99 (208Pb) 07-10
100 ± 6 99 ± 9 98.7 80.6 - 459 188 8.75 (208Pb) 07-04 111 ± 9 122 ± 18 98.8 84.0 - 231 119 8.61 (208Pb) 07-16 141 ± 7 144 ± 18 99.1 87.0 - 103 72 9.15 (204Pb) 07-15 150 ± 7 142 ± 11 99.1 86.2 - 303 261 9.22 (204Pb) 07-02
152 ± 12 157 ± 21 98.9 84.9 - 85 16 8.87 (208Pb) 07-06 250 ± 16 258 ± 23 99.6 94.1 - 131 81 9.18 (204Pb) 07-03 256 ± 7 256 ± 7 99.9 99.1 253 ± 25 2276 1658 9.05 (204Pb) 07-01
276 ± 17 257 ± 20 99.4 90.9 - 92 46 8.95 (204Pb) 07-17 1555 ± 44 1612 ± 26 100.0 99.8 1687 ± 6 1685 54 9.19 (204Pb) 07-13 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.894±0.010 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/17/2004: RSFPb/U = 1.749 x UO+/U+ - 8.989 for UO+/U+ values in the range 7.68< UO+/U+
<8.28. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.8%.
BB1 – Part 2 (Butano Formation; Ben Lomond Mountain) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
90 ± 3 100 ± 7 99.8 96.9 - 321 197 9.01 (208Pb) 05 90 ± 4 104 ± 14 97.9 75.6 - 121 89 9.08 (208Pb) 04 96 ± 4 100 ± 9 99.5 92.1 - 352 152 8.99 (208Pb) 12
103 ± 4 114 ± 6 100.0 100.0 - 631 303 9.00 (208Pb) 03 143 ± 5 146 ± 12 99.6 93.5 - 309 159 9.07 (208Pb) 15 145 ± 5 145 ± 6 99.7 94.6 - 991 86 9.01 (208Pb) 09 154 ± 7 169 ± 16 98.8 83.9 - 122 148 9.01 (204Pb) 02 168 ± 7 169 ± 19 99.2 88.4 - 265 251 9.00 (208Pb) 10 168 ± 8 168 ± 40 97.7 71.5 - 76 92 8.92 (208Pb) 07 201 ± 8 225 ± 20 100.0 104.0 - 121 157 8.99 (208Pb) 06
244 ± 11 233 ± 27 99.0 85.4 - 109 71 9.00 (208Pb) 08 246 ± 9 264 ± 12 100.0 102.0 - 370 242 9.19 (208Pb) 11
273 ± 10 275 ± 14 99.9 98.3 - 233 147 9.01 (208Pb) 01 278 ± 11 258 ± 20 98.9 83.9 - 171 108 8.90 (208Pb) 13 1541 ± 45 1651 ± 28 100.0 103.0 1794 ± 23 252 92 9.74 (208Pb) 14 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.924 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.86; 207Pb/204Pb = 15.62; 208Pb/204Pb = 38.34 ##Session 12/23/2005: RSFPb/U = 2.334 x UO+/U+ - 14.333 for UO+/U+ values in the range 8.46< UO+/U+
<9.28. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 2.6%.
BS1 (Pfeiffer slab; Point Sur) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
94 ± 4 84 ± 11 98.3 75.0 - 231 123 9.43 (204Pb) 02-19 99 ± 3 103 ± 7 99.7 94.8 - 511 198 9.27 (208Pb) 02-14 99 ± 3 101 ± 7 99.7 95.5 - 339 125 9.17 (204Pb) 02-15
103 ± 3 102 ± 9 99.1 86.5 - 867 471 9.08 (208Pb) 02-05 106 ± 6 77 ± 20 97.3 59.8 - 129 95 9.15 (208Pb) 02-04
107 ± 10 124 ± 26 96.0 62.0 - 49 15 9.34 (208Pb) 02-03 107 ± 4 110 ± 7 100.0 99.6 - 424 180 8.90 (208Pb) 02-16 113 ± 5 109 ± 10 99.0 84.6 - 233 76 9.18 (204Pb) 02-06 116 ± 5 114 ± 13 98.7 81.0 - 314 151 9.16 (208Pb) 02-08 120 ± 4 123 ± 9 99.8 96.8 - 1236 934 9.04 (208Pb) 02-12 132 ± 4 153 ± 7 99.5 92.9 - 599 240 9.40 (204Pb) 02-09
1464 ± 46 1564 ± 28 99.8 98.8 1703 ± 11 272 57 9.15 (204Pb) 02-13 1780 ± 50 1758 ± 28 99.9 98.9 1732 ± 16 263 43 9.12 (204Pb) 02-02 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.885±0.018 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 12/21/2001: RSFPb/U = 3.854 x UO+/U+ - 28.787 for UO+/U+ values in the range 8.46< UO+/U+
<9.33. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 6.7%.
BS1A (Pfeiffer slab; Point Sur) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
87 ± 2 84 ± 7 99.3 88.3 - 264 116 9.03 (208Pb) 02-18 91 ± 3 96 ± 13 97.7 71.8 - 211 75 9.75 (208Pb) 02-11 93 ± 3 98 ± 9 100.0 101.0 - 399 164 8.98 (208Pb) 02-12 95 ± 2 96 ± 4 99.8 96.2 - 586 210 9.42 (204Pb) 02-09
100 ± 2 98 ± 9 99.6 93.0 - 287 137 9.46 (208Pb) 02-04 100 ± 2 100 ± 6 100.0 102.0 - 792 385 9.44 (208Pb) 02-03 100 ± 2 101 ± 6 99.8 96.6 - 409 156 8.88 (208Pb) 02-13 101 ± 2 100 ± 5 99.7 95.2 - 536 226 9.36 (208Pb) 02-05 108 ± 2 111 ± 7 99.9 97.7 - 326 135 9.36 (208Pb) 02-06 109 ± 2 112 ± 4 99.8 96.7 - 296 184 9.15 (204Pb) 02-07 110 ± 3 121 ± 12 99.9 98.8 - 211 169 9.61 (208Pb) 02-02 117 ± 5 118 ± 13 99.8 96.0 - 179 111 8.80 (208Pb) 02-15 131 ± 3 136 ± 11 100.0 101.0 - 367 162 8.98 (208Pb) 02-10 151 ± 3 155 ± 8 99.8 97.4 - 204 77 8.87 (208Pb) 02-14
1111 ± 28 1087 ± 21 99.6 95.6 1038 ± 24 169 61 9.26 (204Pb) 02-17 1381 ± 25 1331 ± 21 99.1 91.7 1251 ± 32 112 56 9.25 (204Pb) 02-16 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.941±0.030 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 12/25/2002: RSFPb/U = 2.027 x UO+/U+ - 11.750 for UO+/U+ values in the range 8.47< UO+/U+
<9.88. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 4.4%.
ES1 (Unnamed; Northwest Santa Lucia Range) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
73 ± 3 69 ± 5 99.5 92.2 - 582 440 9.56 (204Pb) 08-12 75 ± 3 79 ± 7 98.7 82.4 - 276 108 9.48 (208Pb) 08-10 91 ± 5 74 ± 15 98.4 74.4 - 134 89 9.02 (204Pb) 08-14 92 ± 2 91 ± 4 99.8 95.9 - 1060 98 9.24 (208Pb) 08-06 93 ± 4 93 ± 9 99.1 86.3 - 786 440 9.44 (208Pb) 08-07 97 ± 3 91 ± 6 99.4 90.6 - 549 271 8.98 (204Pb) 08-11
109 ± 3 112 ± 5 98.9 84.1 - 2042 966 9.32 (204Pb) 08-01 148 ± 13 130 ± 42 96.0 55.0 - 79 47 9.22 (204Pb) 08-05 210 ± 6 205 ± 13 99.0 85.6 - 237 83 9.30 (204Pb) 08-04
247 ± 11 270 ± 19 100.0 107.0 - 152 61 8.94 (208Pb) 08-02 272 ± 18 264 ± 23 99.6 93.5 - 110 52 8.87 (208Pb) 08-09 275 ± 12 278 ± 16 99.4 91.1 - 365 142 8.97 (204Pb) 08-08 285 ± 20 279 ± 29 99.1 87.0 - 340 159 8.72 (208Pb) 08-03 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.885±0.018 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 12/21/2001: RSFPb/U = 3.854 x UO+/U+ - 28.787 for UO+/U+ values in the range 8.46< UO+/U+
<9.33. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 6.7%.
IR1 – Part 1 (Unnamed; Indians Ranch) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
85 ± 1 83 ± 4 99.3 88.7 - 639 107 8.19 (208Pb) 07-07 88 ± 2 94 ± 22 97.1 67.3 - 244 120 8.24 (208Pb) 07-12 92 ± 3 81 ± 40 92.9 39.0 - 117 46 8.37 (208Pb) 07-13 93 ± 2 102 ± 13 98.5 80.2 - 186 106 8.09 (208Pb) 07-03 93 ± 1 86 ± 9 98.5 78.2 - 414 251 8.11 (208Pb) 07-05 95 ± 2 118 ± 32 96.0 63.5 - 148 52 8.07 (208Pb) 07-15 97 ± 1 94 ± 5 99.2 87.3 - 510 274 8.28 (208Pb) 07-11 98 ± 2 86 ± 12 98.0 71.2 - 208 109 8.09 (208Pb) 07-08 99 ± 2 94 ± 18 97.5 67.6 - 220 46 8.12 (208Pb) 07-10
103 ± 1 102 ± 3 99.8 96.6 - 1851 966 8.16 (208Pb) 07-06 108 ± 4 83 ± 24 95.1 45.9 - 236 48 8.11 (208Pb) 07-14 142 ± 2 136 ± 13 99.4 89.5 - 447 442 8.29 (208Pb) 07-01
1093 ± 19 1086 ± 21 99.6 96.1 1071 ± 39 208 88 8.21 (204Pb) 07-09 1346 ± 33 1347 ± 26 99.6 96.4 1350 ± 39 78 74 8.06 (204Pb) 07-02 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.894±0.010 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/17/2004: RSFPb/U = 1.749 x UO+/U+ - 8.989 for UO+/U+ values in the range 7.68< UO+/U+
<8.28. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.8%.
IR1 – Part 2 (Unnamed; Indians Ranch) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
85 ± 1 83 ± 5 99.6 92.9 - 433 191 8.54 (204Pb) 07-19 98 ± 5 102 ± 8 99.5 91.7 - 200 166 8.63 (204Pb) 07-20
106 ± 3 96 ± 6 99.3 88.7 - 587 108 8.38 (204Pb) 07-17 159 ± 4 162 ± 4 99.9 97.9 - 944 22 8.75 (204Pb) 07-16
985 ± 53 1064 ± 38 99.9 99.0 1229 ± 34 100 37 9.01 (204Pb) 07-18 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.863±0.107 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/19/2004: RSFPb/U = 2.820 x UO+/U+ - 18.085 for UO+/U+ values in the range 8.20< UO+/U+
<8.81. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 3.8%.
IR3 (Reliz Canyon or Church Creek Formation; Indians Ranch) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
83 ± 2 74 ± 10 99.1 84.7 - 347 236 8.57 (204Pb) 08-06 84 ± 3 87 ± 4 99.8 97.2 - 197 82 8.80 (204Pb) 08-15 84 ± 2 80 ± 4 99.7 94.3 - 372 420 8.45 (204Pb) 08-17 90 ± 2 86 ± 6 99.5 91.6 - 206 276 8.66 (204Pb) 08-12 94 ± 2 102 ± 6 99.7 95.7 - 117 162 8.56 (204Pb) 08-18
100 ± 3 95 ± 7 99.3 88.2 - 240 150 8.60 (204Pb) 08-16 109 ± 3 120 ± 8 99.8 97.3 - 116 57 8.59 (204Pb) 08-08 115 ± 8 119 ± 9 99.9 97.6 - 164 64 8.13 (204Pb) 08-02 119 ± 2 116 ± 6 99.6 94.0 - 193 156 8.65 (204Pb) 08-11 145 ± 8 140 ± 18 99.3 88.7 - 86 113 8.63 (204Pb) 08-09 146 ± 9 142 ± 24 99.2 87.1 - 61 72 8.83 (204Pb) 08-25 151 ± 4 141 ± 8 99.3 88.6 - 258 236 8.59 (204Pb) 08-21 154 ± 7 158 ± 19 99.1 87.0 - 61 60 8.46 (204Pb) 08-26 156 ± 6 146 ± 9 99.5 91.3 - 151 236 8.62 (204Pb) 08-19 160 ± 7 143 ± 10 99.6 92.8 - 134 121 8.56 (204Pb) 08-13 162 ± 4 157 ± 5 99.7 95.0 - 521 332 8.71 (204Pb) 08-23
239 ± 12 424 ± 20 99.4 95.2 1611 ± 51 120 28 8.81 (204Pb) 08-24 507 ± 11 739 ± 13 100.0 99.6 1527 ± 12 774 279 8.65 (204Pb) 08-10 1364 ± 31 1380 ± 20 100.0 99.9 1406 ± 25 145 172 8.53 (204Pb) 08-20 1597 ± 42 1626 ± 28 99.9 99.3 1662 ± 14 261 112 8.60 (204Pb) 08-07 1729 ± 43 1688 ± 25 99.9 99.5 1637 ± 26 390 37 8.42 (204Pb) 08-22 2370 ± 42 2430 ± 19 100.0 99.8 2480 ± 7 1354 611 8.71 (204Pb) 08-14 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.863±0.107 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/19/2004: RSFPb/U = 2.820 x UO+/U+ - 18.085 for UO+/U+ values in the range 8.20< UO+/U+
<8.81. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 3.8%.
IR4 (Church Creek Formation; Indians Ranch) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
68 ± 5 77 ± 9 99.0 87.0 - 268 204 9.26 (208Pb) 22 71 ± 3 69 ± 9 99.1 86.4 - 373 518 9.30 (208Pb) 04 72 ± 3 76 ± 17 94.6 51.5 - 141 136 9.14 (208Pb) 08 74 ± 4 73 ± 8 98.7 81.7 - 470 364 9.14 (204Pb) 17 74 ± 4 84 ± 12 97.7 73.5 - 216 111 9.25 (208Pb) 25 79 ± 3 75 ± 17 97.3 66.2 - 140 102 8.91 (208Pb) 27 80 ± 3 83 ± 8 99.7 95.6 - 359 337 8.89 (208Pb) 11 87 ± 6 105 ± 29 96.4 65.5 - 75 73 8.90 (208Pb) 14 88 ± 3 86 ± 7 98.9 84.0 - 543 612 8.92 (208Pb) 10
106 ± 4 104 ± 11 99.2 87.9 - 369 188 9.02 (208Pb) 26 149 ± 14 155 ± 30 97.8 73.7 - 65 94 8.97 (204Pb) 18 154 ± 8 143 ± 37 97.2 65.1 - 82 68 8.86 (208Pb) 9 165 ± 9 163 ± 17 98.8 82.6 - 173 94 9.00 (208Pb) 19
173 ± 11 170 ± 13 99.1 86.4 - 328 87 9.19 (204Pb) 21 230 ± 8 237 ± 8 100.0 101.0 - 788 139 9.11 (208Pb) 28
246 ± 10 248 ± 10 100.0 101.0 - 698 291 8.89 (208Pb) 29 251 ± 9 248 ± 9 99.8 96.4 - 701 914 8.98 (204Pb) 05
256 ± 15 237 ± 46 96.9 63.6 - 53 37 8.83 (204Pb) 03 572 ± 27 598 ± 23 99.7 96.1 695 ± 29 523 174 9.01 (204Pb) 15 1005 ± 37 1226 ± 28 99.9 98.8 1639 ± 11 504 528 8.87 (204Pb) 01 1169 ± 94 1230 ± 66 99.9 98.9 1337 ± 32 130 109 9.80 (204Pb) 20 1458 ± 54 1431 ± 32 99.7 97.3 1390 ± 19 189 89 8.76 (204Pb) 02 1563 ± 61 1624 ± 35 99.9 99.3 1703 ± 8 1941 157 9.15 (204Pb) 12
1614 ± 141 1629 ± 79 99.2 93.9 1647 ± 36 140 138 9.01 (204Pb) 24 1651 ± 106 1665 ± 58 99.8 98.7 1683 ± 32 119 72 8.96 (204Pb) 16 1659 ± 60 1661 ± 34 99.8 98.5 1664 ± 23 210 126 8.79 (204Pb) 06 1669 ± 63 1663 ± 37 99.8 98.3 1656 ± 17 487 195 8.97 (204Pb) 13 1679 ± 55 1669 ± 32 99.6 96.5 1656 ± 15 585 134 8.91 (204Pb) 07 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.924 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.86; 207Pb/204Pb = 15.62; 208Pb/204Pb = 38.34 ##Session 12/23/2005: RSFPb/U = 2.334 x UO+/U+ - 14.333 for UO+/U+ values in the range 8.46< UO+/U+
<9.28. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 2.6%.
IR5 (Merle Formation; Indians Ranch) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
68 ± 3 71 ± 4 99.9 98.1 - 334 160 8.87 (204Pb) 12-23 73 ± 3 80 ± 22 101.0 110.0 - 250 194 8.55 (208Pb) 12-17 79 ± 3 78 ± 7 99.7 94.4 - 235 197 8.63 (204Pb) 12-10 80 ± 3 75 ± 8 99.3 87.9 - 255 45 8.73 (204Pb) 12-11 81 ± 2 85 ± 14 100.0 102.0 - 557 262 8.65 (208Pb) 12-09 81 ± 2 80 ± 5 99.7 95.6 - 293 161 8.56 (204Pb) 12-16 82 ± 3 80 ± 6 99.4 89.9 - 349 160 8.66 (204Pb) 12-18 82 ± 5 78 ± 11 99.0 84.6 - 164 52 8.26 (204Pb) 12-05 84 ± 3 88 ± 7 99.5 91.9 - 243 180 8.42 (204Pb) 12-20 86 ± 2 83 ± 4 99.7 94.1 - 465 371 8.52 (204Pb) 12-04 90 ± 3 90 ± 5 99.7 95.1 - 267 76 8.59 (204Pb) 12-06 92 ± 6 98 ± 10 99.7 95.8 - 226 101 8.12 (204Pb) 12-19 93 ± 2 91 ± 5 99.7 95.0 - 363 212 8.40 (204Pb) 12-02 95 ± 4 103 ± 8 99.8 96.8 - 206 109 8.28 (204Pb) 12-03 97 ± 2 92 ± 7 99.7 95.1 - 131 55 8.63 (204Pb) 12-01 97 ± 2 96 ± 2 99.9 98.3 - 627 193 8.66 (204Pb) 12-15 99 ± 3 101 ± 3 100.0 99.5 - 984 273 8.83 (204Pb) 12-07
100 ± 3 98 ± 6 99.7 94.2 - 453 78 8.37 (204Pb) 12-22 132 ± 5 141 ± 5 99.9 98.3 - 329 98 8.38 (204Pb) 12-21 136 ± 5 149 ± 6 100.0 100.0 - 107 60 8.77 (204Pb) 12-14
249 ± 22 239 ± 24 99.7 95.7 - 221 74 7.98 (204Pb) 12-24 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.863±0.107 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 03/19/2004: RSFPb/U = 2.820 x UO+/U+ - 18.085 for UO+/U+ values in the range 8.20< UO+/U+
<8.81. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 3.8%.
LP1 (Unnamed; San Rafael Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
85 ± 3 82 ± 5 99.6 92.4 - 345 151 8.85 (204Pb) 14-16 85 ± 4 81 ± 7 99.1 86.3 - 339 118 8.34 (204Pb) 14-08 88 ± 4 88 ± 6 99.8 96.6 - 377 123 8.99 (204Pb) 14-17 89 ± 2 90 ± 4 99.9 98.4 - 448 189 8.60 (204Pb) 14-10 89 ± 4 90 ± 18 100.0 105.0 - 171 85 8.64 (208Pb) 14-11 90 ± 3 81 ± 9 99.1 84.3 - 222 125 8.31 (204Pb) 14-06 90 ± 3 87 ± 5 99.6 93.7 - 461 173 8.79 (204Pb) 14-09 91 ± 3 90 ± 3 99.8 96.5 - 982 548 8.50 (204Pb) 14-13 93 ± 6 87 ± 7 99.8 96.1 - 418 159 8.14 (204Pb) 14-12 96 ± 3 93 ± 7 99.5 92.3 - 163 88 8.53 (204Pb) 14-04 98 ± 3 100 ± 16 99.0 85.5 - 232 85 8.57 (208Pb) 14-03
101 ± 5 93 ± 8 99.4 90.5 - 173 41 8.68 (204Pb) 14-14 103 ± 4 112 ± 10 99.8 96.5 - 168 66 8.54 (204Pb) 14-02 124 ± 2 122 ± 4 99.8 97.0 - 547 191 8.50 (204Pb) 14-01 144 ± 6 137 ± 9 99.6 93.1 - 297 87 8.39 (204Pb) 14-07
†Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.863±0.107 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 03/19/2004: RSFPb/U = 2.820 x UO+/U+ - 18.085 for UO+/U+ values in the range 8.20< UO+/U+
<8.81. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 3.8%.
LP3 (Juncal Formation; San Rafael Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
68 ± 2 78 ± 21 100.0 102.0 - 124 93 8.71 (208Pb) 15-15 72 ± 2 75 ± 9 99.7 95.2 - 130 26 8.70 (204Pb) 15-07 78 ± 3 72 ± 15 98.7 79.5 - 134 83 8.61 (204Pb) 15-03 90 ± 3 91 ± 6 99.4 90.1 - 349 63 8.54 (204Pb) 15-02 96 ± 5 98 ± 7 99.8 96.0 - 124 86 8.65 (204Pb) 15-05
102 ± 4 100 ± 15 99.2 86.9 - 178 132 8.29 (204Pb) 15-08 148 ± 6 147 ± 8 99.7 95.7 - 339 379 8.92 (204Pb) 15-14 152 ± 7 152 ± 7 100.0 99.5 - 611 648 9.00 (204Pb) 15-11 160 ± 4 162 ± 6 100.0 100.0 - 198 103 8.69 (204Pb) 15-12 179 ± 4 175 ± 4 99.9 98.4 - 696 581 8.58 (204Pb) 15-01
1407 ± 51 1391 ± 36 99.4 94.4 1366 ± 38 157 94 8.57 (204Pb) 15-09 1508 ± 45 1604 ± 31 99.9 99.6 1733 ± 22 192 65 8.81 (204Pb) 15-13 1654 ± 43 1672 ± 26 99.9 99.0 1695 ± 14 362 327 8.76 (204Pb) 15-10 1661 ± 34 1621 ± 20 99.9 98.9 1571 ± 19 324 178 8.43 (204Pb) 15-04 1680 ± 39 1698 ± 22 99.9 99.1 1721 ± 14 346 149 8.66 (204Pb) 15-06 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.863±0.107 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/19/2004: RSFPb/U = 2.820 x UO+/U+ - 18.085 for UO+/U+ values in the range 8.20< UO+/U+
<8.81. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 3.8%.
LP7 (Cozy Dell Shale; San Rafael Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
66 ± 3 64 ± 6 99.4 90.8 - 189 36 7.78 (208Pb) 02-12 68 ± 3 72 ± 4 99.9 98.4 - 840 134 7.92 (208Pb) 02-05 71 ± 3 63 ± 11 98.9 82.2 - 204 118 7.92 (208Pb) 02-11 85 ± 4 89 ± 24 93.8 47.3 - 268 16 7.37 (208Pb) 02-08 88 ± 3 81 ± 6 99.1 84.6 - 404 136 7.19 (208Pb) 02-02 94 ± 2 92 ± 7 99.6 93.1 - 322 150 7.53 (208Pb) 02-06
123 ± 4 118 ± 6 98.8 82.1 - 723 409 7.66 (204Pb) 02-16 163 ± 4 166 ± 23 99.8 96.7 - 256 419 7.48 (208Pb) 02-03
266 ± 10 240 ± 19 99.0 83.9 - 114 25 7.34 (208Pb) 02-07 1184 ± 31 1314 ± 22 99.6 97.0 1534 ± 9 1520 390 7.74 (204Pb) 02-10 1463 ± 46 1483 ± 36 98.5 88.3 1512 ± 49 308 168 7.74 (204Pb) 02-13 1505 ± 53 1583 ± 32 100.0 99.7 1688 ± 10 335 91 7.87 (204Pb) 02-15 1617 ± 55 1664 ± 35 99.9 99.3 1723 ± 19 166 56 7.66 (204Pb) 02-14 1660 ± 37 1675 ± 22 99.9 99.1 1693 ± 13 659 166 7.54 (204Pb) 02-09 1779 ± 82 1716 ± 46 99.9 99.5 1641 ± 23 211 50 7.17 (204Pb) 02-01 1986 ± 62 1815 ± 32 99.4 94.9 1626 ± 16 781 76 7.20 (204Pb) 02-04 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.871±0.014 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/18/2004: RSFPb/U = 2.310x UO+/U+ - 12.904 for UO+/U+ values in the range 6.97< UO+/U+
<8.05. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 7.0%.
LP9 (Unnamed; San Rafael Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
89 ± 3 92 ± 9 99.3 89.2 - 145 58 7.63 (208Pb) 03-08 93 ± 3 90 ± 7 99.7 95.5 - 716 362 7.60 (208Pb) 03-11 98 ± 2 95 ± 6 99.6 93.1 - 730 370 7.50 (208Pb) 03-09 99 ± 3 103 ± 5 99.9 98.1 - 543 188 7.57 (208Pb) 03-07
100 ± 3 97 ± 10 99.3 89.0 - 425 190 7.47 (208Pb) 03-14 104 ± 5 106 ± 7 99.2 87.4 - 280 53 7.33 (208Pb) 03-01 105 ± 4 99 ± 9 99.4 89.9 - 364 170 7.34 (208Pb) 03-15 107 ± 2 101 ± 7 99.5 91.2 - 234 69 7.46 (208Pb) 03-10 110 ± 4 114 ± 7 100.0 102.0 - 493 203 7.34 (208Pb) 03-04 116 ± 4 115 ± 5 99.9 97.9 - 534 135 7.79 (208Pb) 03-06 129 ± 5 120 ± 12 99.5 92.3 - 292 164 7.42 (208Pb) 03-05
136 ± 12 145 ± 14 100.0 99.7 - 456 157 6.91 (208Pb) 03-02 149 ± 9 154 ± 15 99.7 95.9 - 175 52 7.21 (208Pb) 03-03
663 ± 23 766 ± 20 99.9 98.9 1078 ± 24 276 61 7.83 (204Pb) 03-12 1027 ± 22 1041 ± 14 99.9 99.2 1072 ± 30 320 97 7.51 (204Pb) 03-13 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.871±0.014 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/18/2004: RSFPb/U = 2.310x UO+/U+ - 12.904 for UO+/U+ values in the range 6.97< UO+/U+
<8.05. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 7.0%.
LP10 (Unnamed; San Rafael Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
88 ± 3 87 ± 5 99.7 95.6 - 651 349 7.79 (208Pb) 04-14 93 ± 3 89 ± 8 99.3 88.4 - 422 211 7.69 (208Pb) 04-13 98 ± 4 95 ± 13 99.2 87.7 - 144 74 7.51 (208Pb) 04-11 99 ± 3 100 ± 12 99.9 98.9 - 210 79 7.54 (208Pb) 04-12
101 ± 3 104 ± 10 99.8 96.3 - 299 159 7.59 (208Pb) 04-08 105 ± 3 98 ± 11 99.5 91.9 - 247 121 7.51 (208Pb) 04-09 114 ± 4 104 ± 10 99.4 90.4 - 282 126 7.40 (208Pb) 04-07 119 ± 3 123 ± 8 100.0 99.9 - 528 259 7.36 (208Pb) 04-03 121 ± 5 134 ± 10 100.0 103.0 - 186 106 7.60 (208Pb) 04-10 123 ± 4 124 ± 7 99.9 98.0 - 533 277 7.26 (208Pb) 04-04 124 ± 8 114 ± 13 99.0 83.8 - 186 103 7.08 (208Pb) 04-16
146 ± 11 125 ± 18 98.7 79.0 - 146 44 7.01 (208Pb) 04-01 162 ± 9 164 ± 26 99.3 89.3 - 86 39 7.57 (208Pb) 04-15 170 ± 9 134 ± 34 96.8 58.0 - 78 41 7.16 (208Pb) 04-02
171 ± 11 164 ± 25 98.6 80.1 - 80 23 7.52 (208Pb) 04-05 196 ± 12 206 ± 32 98.6 81.6 - 54 22 7.19 (208Pb) 04-06 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.871±0.014 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 03/18/2004: RSFPb/U = 2.310x UO+/U+ - 12.904 for UO+/U+ values in the range 6.97< UO+/U+
<8.05. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 7.0%.
LP11 (Unnamed; San Rafael Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
94 ± 3 95 ± 7 99.6 93.8 - 316 110 7.46 (208Pb) 06-14 94 ± 2 97 ± 6 99.7 95.5 - 554 155 7.53 (208Pb) 06-12 98 ± 3 96 ± 8 99.7 94.4 - 197 55 7.42 (208Pb) 06-08
100 ± 3 102 ± 6 99.6 93.0 - 304 121 7.50 (208Pb) 06-10 105 ± 3 107 ± 5 100.0 99.7 - 1296 440 7.53 (208Pb) 06-07 107 ± 3 119 ± 9 100.0 105.0 - 243 146 7.43 (208Pb) 06-09 108 ± 3 110 ± 10 99.9 97.8 - 239 193 7.40 (208Pb) 06-11 109 ± 5 113 ± 11 99.3 90.1 - 233 181 7.47 (208Pb) 06-03 115 ± 4 108 ± 7 99.5 91.4 - 391 159 7.26 (208Pb) 06-06 117 ± 3 113 ± 6 99.7 94.4 - 703 318 7.53 (208Pb) 06-05 123 ± 3 122 ± 7 99.6 94.0 - 673 368 7.45 (208Pb) 06-13 137 ± 8 135 ± 11 99.6 93.1 - 644 317 7.06 (208Pb) 05-01
191 ± 12 205 ± 16 100.0 100.0 - 170 74 7.43 (208Pb) 06-15 201 ± 8 202 ± 11 100.0 101.0 - 258 58 7.25 (208Pb) 06-04
2096 ± 72 1975 ± 36 100.0 99.9 1850 ± 12 265 141 7.30 (204Pb) 06-02 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.871±0.014 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/18/2004: RSFPb/U = 2.310x UO+/U+ - 12.904 for UO+/U+ values in the range 6.97< UO+/U+
<8.05. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 7.0%.
LP12 – Part 1 (Jalama(?) Formation; Santa Ynez Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
74 ± 1 78 ± 6 99.8 97.0 - 579 301 7.96 (208Pb) 02-04 75 ± 1 78 ± 7 99.5 92.4 - 798 408 8.28 (208Pb) 02-09 76 ± 1 80 ± 8 99.6 93.5 - 844 620 8.05 (208Pb) 02-07 81 ± 2 79 ± 19 97.3 66.9 - 209 168 8.28 (208Pb) 02-06 86 ± 1 102 ± 10 99.8 97.1 - 247 168 8.14 (208Pb) 02-10 87 ± 1 86 ± 13 98.6 80.3 - 242 133 8.03 (208Pb) 02-05
130 ± 8 157 ± 17 100.0 104.0 - 199 138 8.75 (208Pb) 02-14 158 ± 3 164 ± 19 99.9 98.7 - 308 255 8.39 (208Pb) 02-08 268 ± 4 260 ± 14 99.7 95.3 - 257 99 7.94 (208Pb) 02-13 274 ± 6 290 ± 27 99.4 92.0 - 114 60 8.03 (208Pb) 02-12
531 ± 10 671 ± 20 99.8 98.1 1176 ± 50 183 57 8.07 (204Pb) 02-11 1454 ± 39 1573 ± 24 99.9 99.5 1737 ± 21 170 92 8.98 (204Pb) 02-01 1789 ± 35 1767 ± 17 99.7 98.1 1741 ± 32 143 105 7.87 (204Pb) 02-15 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.862±0.029 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/15/2004: RSFPb/U = 1.519 x UO+/U+ - 7.159 for UO+/U+ values in the range 7.68< UO+/U+
<8.17. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.2%.
LP12 – Part 2 (Jalama(?) Formation; Santa Ynez Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
75 ± 3 74 ± 14 97.7 70.9 - 201 141 9.11 (208Pb) 06 80 ± 3 85 ± 7 99.8 97.0 - 666 309 9.09 (208Pb) 05 81 ± 3 81 ± 11 98.9 83.5 - 329 235 8.94 (208Pb) 03 81 ± 4 92 ± 13 98.0 76.4 - 215 154 9.03 (208Pb) 14 83 ± 3 83 ± 15 97.0 65.1 - 262 140 9.10 (208Pb) 08 84 ± 3 83 ± 7 98.9 83.9 - 266 15 9.11 (208Pb) 15 84 ± 3 88 ± 7 99.6 94.1 - 547 248 9.08 (208Pb) 16 86 ± 3 101 ± 9 100.0 99.9 - 359 260 9.14 (208Pb) 07 87 ± 5 99 ± 35 93.8 49.7 - 59 103 8.93 (208Pb) 01 90 ± 4 52 ± 29 92.6 28.8 - 86 88 8.91 (208Pb) 09 91 ± 3 97 ± 10 99.0 86.1 - 264 151 9.10 (208Pb) 04 91 ± 3 94 ± 7 99.3 89.9 - 466 125 9.32 (208Pb) 12 98 ± 4 102 ± 7 99.5 91.9 - 432 206 8.99 (208Pb) 17
102 ± 4 113 ± 11 99.3 90.3 - 201 86 9.09 (208Pb) 11 1314 ± 75 1324 ± 86 98.2 85.2 1340 ± 171 16 12 9.40 (204Pb) 10 1671 ± 56 1666 ± 30 99.8 98.6 1661 ± 16 995 295 9.23 (204Pb) 13 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.924 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.86; 207Pb/204Pb = 15.62; 208Pb/204Pb = 38.34 ##Session 12/23/2005: RSFPb/U = 2.334 x UO+/U+ - 14.333 for UO+/U+ values in the range 8.46< UO+/U+
<9.28. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 2.6%.
LP13 (Coldwater Sandstone; Santa Ynez Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
76 ± 3 78 ± 38 94.8 50.9 - 51 15 8.06 (208Pb) 03-12 82 ± 1 102 ± 8 100.0 101.0 - 1047 619 8.55 (208Pb) 03-10 91 ± 2 89 ± 21 97.1 64.9 - 153 49 8.12 (208Pb) 03-06
100 ± 2 112 ± 15 99.3 89.8 - 274 114 8.05 (208Pb) 03-15 147 ± 4 184 ± 26 100.0 105.0 - 152 205 8.25 (208Pb) 03-09 156 ± 3 154 ± 15 99.7 95.2 - 485 381 8.11 (208Pb) 03-08 157 ± 3 172 ± 19 100.0 106.0 - 427 425 8.37 (208Pb) 03-05
1315 ± 28 1338 ± 23 99.6 96.2 1377 ± 33 147 51 8.14 (204Pb) 03-07 1364 ± 18 1395 ± 12 99.9 99.3 1444 ± 26 188 70 8.21 (204Pb) 03-13 1386 ± 14 1399 ± 9 99.9 99.4 1417 ± 19 192 79 7.96 (204Pb) 03-04 1406 ± 13 1407 ± 9 99.9 99.1 1409 ± 13 321 130 8.08 (204Pb) 03-01 1416 ± 16 1423 ± 8 99.9 99.0 1434 ± 15 358 225 7.89 (204Pb) 03-02 1615 ± 22 1645 ± 15 100.0 99.8 1685 ± 14 349 85 8.10 (204Pb) 03-11 1726 ± 15 1724 ± 7 100.0 100.0 1722 ± 12 541 266 8.05 (204Pb) 03-14 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.862±0.029 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/15/2004: RSFPb/U = 1.519 x UO+/U+ - 7.159 for UO+/U+ values in the range 7.68< UO+/U+
<8.17. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.2%.
LP14 (Cozy Dell Shale; Santa Ynez Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
69 ± 2 72 ± 9 98.4 78.0 - 141 54 8.44 (208Pb) 04-06 72 ± 2 74 ± 8 99.1 86.8 - 291 200 8.20 (208Pb) 04-10 77 ± 1 78 ± 8 99.0 85.0 - 436 158 8.27 (208Pb) 04-14 77 ± 1 84 ± 7 99.0 85.6 - 414 207 7.79 (208Pb) 04-05 81 ± 3 64 ± 35 93.9 40.1 - 43 13 7.92 (208Pb) 04-01
102 ± 1 114 ± 11 99.8 97.2 - 414 272 8.17 (208Pb) 04-12 165 ± 3 189 ± 29 101.0 111.0 - 307 413 8.09 (208Pb) 04-11 167 ± 2 170 ± 16 99.9 99.2 - 542 468 8.02 (208Pb) 04-08 171 ± 3 185 ± 17 100.0 102.0 - 362 270 7.83 (208Pb) 04-03 172 ± 2 180 ± 30 100.0 104.0 - 781 1207 8.23 (208Pb) 04-02 191 ± 2 209 ± 14 100.0 106.0 - 615 394 7.94 (208Pb) 04-07
1348 ± 14 1366 ± 9 100.0 99.6 1395 ± 11 610 232 8.08 (204Pb) 04-09 1377 ± 14 1367 ± 15 99.6 95.8 1353 ± 30 283 127 8.28 (204Pb) 04-16 1675 ± 24 1697 ± 16 99.9 99.4 1724 ± 22 163 91 8.38 (204Pb) 04-13 1721 ± 34 1692 ± 22 99.7 97.5 1655 ± 32 103 34 7.87 (204Pb) 04-15 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.862±0.029 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/15/2004: RSFPb/U = 1.519 x UO+/U+ - 7.159 for UO+/U+ values in the range 7.68< UO+/U+
<8.17. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.2%.
LP15 (Matilija Sandstone; Santa Ynez Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
77 ± 1 79 ± 5 99.8 96.1 - 1068 578 8.12 (208Pb) 06-11 80 ± 10 79 ± 22 99.0 84.7 - 529 622 7.53 (208Pb) 06-03 98 ± 1 96 ± 10 99.6 92.8 - 598 410 8.07 (208Pb) 06-04
136 ± 2 147 ± 10 100.0 103.0 - 493 118 7.90 (208Pb) 06-14 157 ± 2 161 ± 14 100.0 100.0 - 505 341 8.03 (208Pb) 06-06 176 ± 6 269 ± 68 103.0 139.0 - 129 338 7.95 (208Pb) 06-15 177 ± 3 194 ± 23 100.0 102.0 - 266 276 7.90 (208Pb) 06-13
1202 ± 47 1207 ± 58 99.3 93.3 1217 ± 121 31 29 8.04 (204Pb) 06-07 1226 ± 20 1213 ± 17 99.7 97.2 1189 ± 39 71 114 8.11 (204Pb) 06-09 1256 ± 15 1313 ± 10 99.9 99.5 1406 ± 9 1950 871 7.59 (204Pb) 06-12 1589 ± 17 1618 ± 12 99.8 98.4 1656 ± 16 297 68 8.11 (204Pb) 06-05 1667 ± 28 1658 ± 18 99.7 97.5 1646 ± 19 275 51 8.02 (204Pb) 06-02 1703 ± 14 1704 ± 8 100.0 99.8 1706 ± 10 955 464 8.12 (204Pb) 06-08 1746 ± 30 1724 ± 19 99.9 99.1 1696 ± 18 177 95 8.03 (204Pb) 06-01 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.862±0.029 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/15/2004: RSFPb/U = 1.519 x UO+/U+ - 7.159 for UO+/U+ values in the range 7.68< UO+/U+
<8.17. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.2%.
LV2 (Juncal Formation; Pine Mountain block) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
74 ± 2 72 ± 25 91.8 38.2 - 195 43 9.79 (208Pb) 12-11 101 ± 2 101 ± 10 97.3 67.2 - 375 216 9.84 (208Pb) 12-13
171 ± 13 157 ± 48 90.8 34.5 - 99 116 9.09 (208Pb) 12-06 174 ± 4 174 ± 21 97.2 67.5 - 323 450 9.73 (204Pb) 12-03
1087 ± 78 1129 ± 103 96.2 70.8 1209 ± 230 18 13 10.30 (204Pb) 12-02 1128 ± 33 1152 ± 37 98.2 83.8 1199 ± 65 63 74 9.97 (204Pb) 12-17 1364 ± 37 1343 ± 36 98.3 85.4 1309 ± 69 48 48 9.99 (204Pb) 12-05 1462 ± 19 1439 ± 11 99.9 99.0 1405 ± 9 1392 230 9.74 (204Pb) 12-14 1566 ± 40 1617 ± 24 99.8 98.1 1683 ± 13 301 174 10.10 (204Pb) 12-08 1570 ± 52 1632 ± 39 98.8 91.2 1715 ± 49 39 24 10.10 (204Pb) 12-12 1710 ± 26 1708 ± 14 99.9 99.1 1705 ± 10 742 690 9.79 (204Pb) 12-16 1918 ± 48 1810 ± 25 99.8 98.5 1689 ± 9 752 214 9.60 (204Pb) 12-01 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 1.002±0.016 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 05/03/2002: RSFPb/U = 2.150 x UO+/U+ - 13.924 for UO+/U+ values in the range 9.64< UO+/U+
<9.98. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.9%.
LV3 (Juncal Formation; Pine Mountain block) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
158 ± 8 180 ± 21 100.0 107.0 - 80 98 8.56 (208Pb) 09-18 159 ± 5 164 ± 20 99.8 96.3 - 75 79 8.77 (208Pb) 09-27 169 ± 4 159 ± 16 99.8 96.8 - 206 152 8.60 (208Pb) 09-13 170 ± 3 168 ± 10 99.4 90.0 - 99 134 8.64 (204Pb) 09-09 172 ± 6 151 ± 14 99.1 84.9 - 132 104 8.57 (208Pb) 09-12
227 ± 12 224 ± 14 99.7 95.1 - 192 79 8.51 (208Pb) 09-01 1058 ± 164 1106 ± 109 99.8 98.1 1202 ± 62 54 43 9.02 (204Pb) 09-02 1106 ± 82 1080 ± 85 98.5 85.0 1028 ± 165 6 9 8.95 (204Pb) 09-22 1152 ± 40 1109 ± 33 99.3 93.0 1028 ± 87 16 19 8.73 (204Pb) 09-05 1154 ± 17 1161 ± 12 99.9 99.1 1175 ± 15 251 308 8.71 (204Pb) 09-07 1311 ± 30 1314 ± 20 99.3 93.7 1320 ± 30 136 58 8.66 (204Pb) 09-10 1560 ± 18 1610 ± 11 100.0 99.8 1675 ± 8 1565 68 8.72 (204Pb) 09-11 1769 ± 72 1731 ± 39 99.7 98.0 1685 ± 26 118 47 8.27 (204Pb) 09-04 1820 ± 32 1765 ± 17 99.9 99.6 1702 ± 11 262 127 8.44 (204Pb) 09-16 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.921±0.010 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 12/24/2002: RSFPb/U = 2.450 x UO+/U+ - 15.188 for UO+/U+ values in the range 8.47< UO+/U+
<9.34. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 3.2%.
MM1 (Unnamed; Point San Pedro) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
96 ± 7 97 ± 23 84.4 23.9 - 330 169 9.13 (208Pb) 11-02 102 ± 2 111 ± 14 95.7 58.7 - 478 321 9.87 (204Pb) 11-06 103 ± 4 116 ± 20 95.0 55.3 - 239 285 9.52 (208Pb) 11-23 105 ± 3 101 ± 9 97.8 70.8 - 728 206 9.56 (208Pb) 11-22 158 ± 4 158 ± 36 93.7 46.8 - 127 100 9.72 (208Pb) 11-10 163 ± 5 164 ± 29 95.6 56.4 - 231 248 9.57 (204Pb) 11-01 169 ± 6 166 ± 39 90.2 34.9 - 139 123 9.68 (208Pb) 11-14 171 ± 3 171 ± 13 97.9 73.2 - 472 406 9.92 (204Pb) 11-04 172 ± 3 169 ± 10 99.0 84.7 - 1025 844 9.99 (204Pb) 11-18
1866 ± 25 1809 ± 13 99.7 97.8 1745 ± 10 346 123 9.78 (204Pb) 11-03 1945 ± 60 2313 ± 34 99.0 95.6 2656 ± 21 87 63 10.10 (204Pb) 11-19 1951 ± 53 1842 ± 27 99.9 98.8 1720 ± 9 599 70 9.48 (204Pb) 11-09 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 1.002±0.016 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 05/03/2002: RSFPb/U = 2.150 x UO+/U+ - 13.924 for UO+/U+ values in the range 9.64< UO+/U+
<9.98. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.9%.
MM1A (Unnamed; Point San Pedro) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
75 ± 3 77 ± 5 98.9 84.4 - 724 782 9.35 (204Pb) 03-12 83 ± 2 87 ± 7 99.2 88.2 - 281 144 9.41 (204Pb) 03-22 88 ± 2 88 ± 7 99.2 87.2 - 431 194 9.12 (208Pb) 03-10 93 ± 5 90 ± 9 99.1 86.5 - 337 274 9.06 (204Pb) 03-09 98 ± 2 94 ± 5 99.3 88.0 - 509 343 9.26 (204Pb) 03-02 98 ± 4 97 ± 8 99.2 87.4 - 280 104 9.15 (204Pb) 03-04
104 ± 5 122 ± 21 97.4 71.8 - 119 65 8.93 (208Pb) 03-08 106 ± 5 111 ± 8 99.6 94.1 - 438 141 8.86 (208Pb) 03-25 123 ± 6 119 ± 9 99.3 88.7 - 428 137 8.82 (204Pb) 03-06 143 ± 6 168 ± 10 99.8 97.1 - 164 147 9.33 (204Pb) 03-11 167 ± 8 181 ± 14 99.5 92.6 - 300 215 8.93 (204Pb) 03-01
188 ± 35 193 ± 131 98.5 80.0 - 30 49 8.62 (208Pb) 03-05 210 ± 21 186 ± 30 98.2 74.4 - 131 90 8.72 (204Pb) 03-03 233 ± 17 253 ± 18 99.6 94.1 - 327 120 8.67 (204Pb) 03-29 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.885±0.018 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 12/21/2001: RSFPb/U = 3.854 x UO+/U+ - 28.787 for UO+/U+ values in the range 8.46< UO+/U+
<9.33. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 6.7%.
MM2 (Unnamed; Point San Pedro) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
84 ± 2 82 ± 6 99.6 94.0 - 524 290 8.81 (208Pb) 10-10 90 ± 2 87 ± 10 99.2 87.3 - 154 68 8.76 (208Pb) 10-04 90 ± 1 87 ± 3 99.6 93.8 - 525 173 8.90 (208Pb) 10-01 91 ± 1 86 ± 4 99.6 92.9 - 287 158 9.18 (204Pb) 10-20 94 ± 3 93 ± 7 99.7 95.0 - 462 93 9.22 (208Pb) 10-18 99 ± 2 103 ± 8 100.0 103.0 - 676 521 8.79 (208Pb) 10-17
105 ± 9 105 ± 12 99.9 97.6 - 441 229 8.48 (208Pb) 10-14 144 ± 5 163 ± 29 100.0 106.0 - 85 131 9.02 (208Pb) 10-19 161 ± 3 170 ± 11 100.0 101.0 - 223 184 9.00 (208Pb) 10-09 162 ± 7 173 ± 42 99.9 97.9 - 57 93 8.83 (208Pb) 10-08 163 ± 5 184 ± 16 100.0 106.0 - 516 506 8.68 (208Pb) 10-05 198 ± 4 204 ± 19 99.3 89.7 - 133 125 8.69 (208Pb) 10-02
258 ± 41 254 ± 37 99.9 97.6 - 270 135 8.59 (204Pb) 10-13 1177 ± 27 1334 ± 17 99.9 98.9 1598 ± 12 1773 77 8.97 (204Pb) 10-06 1247 ± 28 1397 ± 14 99.7 97.8 1634 ± 26 1338 280 9.19 (204Pb) 10-12 1739 ± 25 1754 ± 15 99.8 98.7 1773 ± 24 167 124 9.02 (204Pb) 10-21 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.921±0.010 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 12/24/2002: RSFPb/U = 2.450 x UO+/U+ - 15.188 for UO+/U+ values in the range 8.47< UO+/U+
<9.34. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 3.2%.
MM3 – Part 1 (Unnamed; Point San Pedro) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
94 ± 2 87 ± 9 98.8 81.0 - 711 354 9.04 (208Pb) 03-01 109 ± 3 116 ± 14 99.0 86.5 - 158 63 9.51 (208Pb) 03-02 121 ± 3 134 ± 10 94.1 50.7 - 496 195 9.86 (208Pb) 03-07 161 ± 3 175 ± 14 100.0 105.0 - 261 80 9.58 (208Pb) 03-05
†Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.941±0.030 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 12/25/2002: RSFPb/U = 2.027 x UO+/U+ - 11.750 for UO+/U+ values in the range 8.47< UO+/U+
<9.88. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 4.4%.
MM3 – Part 2 (Unnamed; Point San Pedro) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
87 ± 2 84 ± 13 92.4 40.3 - 277 158 7.53 (208Pb) 16-04 91 ± 3 86 ± 10 99.4 89.8 - 560 278 7.37 (208Pb) 16-03 92 ± 4 93 ± 8 99.7 94.5 - 446 228 7.21 (208Pb) 16-11 93 ± 5 85 ± 95 75.9 13.8 - 592 165 7.43 (208Pb) 16-13 95 ± 3 100 ± 13 99.2 87.8 - 419 194 7.20 (208Pb) 16-08 96 ± 4 102 ± 27 97.4 69.7 - 78 41 7.39 (208Pb) 16-05 97 ± 3 102 ± 7 99.1 87.0 - 1097 333 7.42 (208Pb) 16-06
101 ± 3 108 ± 8 99.9 98.3 - 389 116 7.38 (208Pb) 16-02 105 ± 4 110 ± 8 99.9 98.2 - 684 275 7.21 (208Pb) 16-15 106 ± 5 105 ± 7 99.5 92.3 - 504 102 7.72 (208Pb) 16-16 108 ± 3 114 ± 8 100.0 99.3 - 629 216 7.51 (208Pb) 16-07 125 ± 4 140 ± 8 100.0 100.0 - 512 185 7.34 (208Pb) 16-01 145 ± 5 144 ± 12 99.2 87.7 - 162 57 7.39 (208Pb) 16-10 164 ± 3 169 ± 16 100.0 102.0 - 984 1238 7.44 (208Pb) 16-09
250 ± 12 243 ± 20 99.6 94.3 - 287 135 7.35 (208Pb) 16-14 1550 ± 30 1622 ± 17 100.0 100.0 1716 ± 12 928 58 7.57 (208Pb) 16-12 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.871±0.014 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/18/2004: RSFPb/U = 2.310x UO+/U+ - 12.904 for UO+/U+ values in the range 6.97< UO+/U+
<8.05. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 7.0%.
MO1 (Carmelo Formation; Point Lobos) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
73 ± 3 69 ± 5 99.5 92.2 - 582 440 9.56 (204Pb) 08-12 75 ± 3 79 ± 7 98.7 82.4 - 276 108 9.48 (208Pb) 08-10 91 ± 5 74 ± 15 98.4 74.4 - 134 89 9.02 (204Pb) 08-14 92 ± 2 91 ± 4 99.8 95.9 - 1060 98 9.24 (208Pb) 08-06 93 ± 4 93 ± 9 99.1 86.3 - 786 440 9.44 (208Pb) 08-07 97 ± 3 91 ± 6 99.4 90.6 - 549 271 8.98 (204Pb) 08-11
109 ± 3 112 ± 5 98.9 84.1 - 2042 966 9.32 (204Pb) 08-01 148 ± 13 130 ± 42 96.0 55.0 - 79 47 9.22 (204Pb) 08-05 210 ± 6 205 ± 13 99.0 85.6 - 237 83 9.30 (204Pb) 08-04
247 ± 11 270 ± 19 100.0 107.0 - 152 61 8.94 (208Pb) 08-02 272 ± 18 264 ± 23 99.6 93.5 - 110 52 8.87 (208Pb) 08-09 275 ± 12 278 ± 16 99.4 91.1 - 365 142 8.97 (204Pb) 08-08 285 ± 20 279 ± 29 99.1 87.0 - 340 159 8.72 (208Pb) 08-03 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 1.004±0.050 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 05/02/2002: RSFPb/U = 0.804 x UO+/U+ - 1.152 for UO+/U+ values in the range 9.04< UO+/U+
<10.60. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.3%.
MP1 (Unnamed; Sierra Madre Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
75 ± 3 70 ± 16 98.1 73.5 - 449 413 8.73 (208Pb) 02-19 76 ± 7 86 ± 110 75.9 16.6 - 101 110 9.50 (208Pb) 02-28 83 ± 2 65 ± 21 93.8 40.0 - 220 188 8.67 (208Pb) 02-11
224 ± 4 216 ± 10 99.1 87.1 - 989 610 8.74 (208Pb) 02-18 255 ± 5 248 ± 18 98.5 79.8 - 650 285 8.66 (208Pb) 02-06
1131 ± 32 1106 ± 36 98.6 86.0 1055 ± 78 50 47 9.34 (204Pb) 02-25 1146 ± 39 1137 ± 39 98.3 83.8 1119 ± 103 86 25 8.73 (204Pb) 02-04 1149 ± 48 1195 ± 74 97.7 80.7 1280 ± 179 45 43 8.78 (204Pb) 02-10 1195 ± 20 1233 ± 18 99.6 96.1 1299 ± 31 471 248 8.85 (204Pb) 02-16 1334 ± 23 1354 ± 17 99.5 95.6 1384 ± 24 250 94 9.48 (204Pb) 02-31 1379 ± 43 1492 ± 31 99.7 97.2 1658 ± 24 142 170 8.80 (204Pb) 02-24 1588 ± 22 1622 ± 14 99.5 95.9 1667 ± 14 634 301 8.84 (204Pb) 02-02 1600 ± 52 1647 ± 33 99.8 98.1 1708 ± 39 246 115 8.93 (204Pb) 02-23 1735 ± 66 1703 ± 40 99.1 93.3 1664 ± 42 112 55 8.74 (204Pb) 02-14 1762 ± 24 1733 ± 15 99.6 96.8 1698 ± 19 336 45 9.07 (204Pb) 02-07 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.945±0.011 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 12/22/2002: RSFPb/U = 2.574 x UO+/U+ - 16.253 for UO+/U+ values in the range 8.51< UO+/U+
<9.34. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 4.0%.
MP2 (Unnamed; Sierra Madre Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
161 ± 2 167 ± 12 98.8 83.0 - 653 1145 9.88 (204Pb) 07-13 173 ± 8 172 ± 17 95.1 53.2 - 359 260 9.34 (208Pb) 07-07 174 ± 6 176 ± 40 93.9 47.8 - 107 106 9.64 (208Pb) 07-11 175 ± 3 181 ± 12 98.5 80.5 - 481 496 9.74 (204Pb) 07-02 177 ± 6 183 ± 21 96.6 63.4 - 191 106 9.59 (208Pb) 07-05 187 ± 7 190 ± 17 97.5 70.7 - 549 442 9.43 (204Pb) 07-01
1209 ± 30 1225 ± 43 98.4 86.0 1254 ± 104 58 43 9.67 (204Pb) 07-12 1404 ± 21 1391 ± 18 99.5 95.3 1370 ± 26 258 129 9.75 (204Pb) 07-10 1609 ± 28 1636 ± 17 99.8 98.7 1671 ± 9 703 134 9.93 (204Pb) 07-09 1740 ± 60 1727 ± 37 99.0 92.7 1712 ± 40 55 33 9.65 (204Pb) 07-08 1748 ± 32 1716 ± 23 99.2 94.0 1676 ± 30 115 76 9.64 (204Pb) 07-03 1864 ± 61 1786 ± 33 99.5 96.1 1695 ± 19 159 51 9.45 (204Pb) 07-06 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 1.002±0.016 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 05/03/2002: RSFPb/U = 2.150 x UO+/U+ - 13.924 for UO+/U+ values in the range 9.64< UO+/U+
<9.98. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.9%.
MP3 (Unnamed; Sierra Madre Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
78 ± 3 82 ± 16 91.9 40.5 - 225 122 9.61 (208Pb) 10-10 78 ± 2 69 ± 22 93.0 40.0 - 310 200 9.63 (204Pb) 10-02 86 ± 2 76 ± 11 95.7 52.8 - 867 930 9.52 (204Pb) 10-12
157 ± 4 150 ± 26 96.1 58.2 - 300 319 9.95 (204Pb) 10-13 163 ± 3 158 ± 21 97.4 68.6 - 336 506 9.87 (204Pb) 10-08
1167 ± 38 1193 ± 44 98.6 87.5 1240 ± 88 79 74 10.00 (204Pb) 10-05 1195 ± 29 1216 ± 43 98.3 85.0 1253 ± 91 56 22 9.70 (204Pb) 10-09 1393 ± 21 1389 ± 22 99.1 92.2 1383 ± 43 132 58 9.79 (204Pb) 10-04 1426 ± 27 1421 ± 33 98.4 87.0 1415 ± 65 89 71 9.76 (204Pb) 10-06 1476 ± 31 1459 ± 17 99.7 96.9 1433 ± 17 629 189 9.68 (204Pb) 10-01 1688 ± 16 1682 ± 9 99.9 99.5 1674 ± 7 1126 37 9.88 (204Pb) 10-03 1700 ± 32 1684 ± 25 99.1 93.4 1664 ± 46 102 85 9.75 (204Pb) 10-11 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 1.002±0.016 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 05/03/2002: RSFPb/U = 2.150 x UO+/U+ - 13.924 for UO+/U+ values in the range 9.64< UO+/U+
<9.98. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.9%.
OR432 – Part 1 (Maniobra Formation; Orocopia Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
74 ± 3 49 ± 24 95.4 43.4 - 191 306 9.75 (204Pb) 09-10 173 ± 6 184 ± 9 99.8 96.4 - 448 609 9.96 (204Pb) 09-16
181 ± 12 184 ± 18 99.3 89.5 - 242 253 8.76 (204Pb) 09-21 229 ± 19 215 ± 46 98.0 73.1 - 93 45 9.73 (204Pb) 09-01 1242 ± 58 1228 ± 39 99.5 95.3 1202 ± 47 184 195 9.79 (204Pb) 09-14 1628 ± 38 1643 ± 26 99.8 98.1 1663 ± 24 181 76 9.90 (204Pb) 09-02 1648 ± 48 1661 ± 34 99.7 97.8 1678 ± 33 185 106 9.79 (204Pb) 09-17 1670 ± 47 1687 ± 29 99.7 98.0 1709 ± 34 156 31 9.89 (204Pb) 09-07 1685 ± 69 1666 ± 37 99.4 95.4 1642 ± 42 65 54 9.79 (204Pb) 09-06 1686 ± 30 1685 ± 15 99.9 98.9 1683 ± 22 375 149 9.72 (204Pb) 09-04 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.862±0.016 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 07/15/2003: RSFPb/U = 2.725 x UO+/U+ - 18.676 for UO+/U+ values in the range 9.25< UO+/U+
<10.10. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 2.8%.
OR432 – Part 2 (Maniobra Formation; Orocopia Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
168 ± 3 167 ± 23 99.3 90.0 - 320 327 7.86 (208Pb) 13-06 169 ± 2 167 ± 18 99.4 90.5 - 333 300 7.82 (208Pb) 13-10 170 ± 2 176 ± 18 100.0 100.0 - 444 391 7.68 (208Pb) 13-02
1176 ± 11 1173 ± 10 99.8 98.2 1166 ± 20 186 90 7.95 (204Pb) 13-08 1308 ± 15 1324 ± 18 99.5 95.3 1350 ± 37 134 96 8.19 (204Pb) 13-13 1460 ± 21 1432 ± 18 99.8 98.2 1389 ± 36 104 148 7.75 (204Pb) 13-11 1468 ± 31 1518 ± 27 98.9 91.0 1589 ± 51 106 85 7.35 (204Pb) 13-03 1543 ± 15 1598 ± 10 99.8 98.7 1670 ± 17 239 115 8.21 (204Pb) 13-16 1574 ± 23 1598 ± 15 99.9 99.6 1631 ± 17 194 92 7.65 (204Pb) 13-01 1665 ± 15 1660 ± 13 99.7 97.7 1653 ± 22 259 151 7.83 (204Pb) 13-09 1669 ± 26 1682 ± 18 99.8 98.3 1698 ± 17 113 92 7.99 (204Pb) 13-12 1687 ± 52 1676 ± 37 99.5 95.8 1663 ± 39 69 50 7.73 (204Pb) 13-07 1740 ± 38 1694 ± 22 99.7 97.8 1637 ± 18 235 66 7.74 (204Pb) 13-04 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.862±0.029 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/15/2004: RSFPb/U = 1.519 x UO+/U+ - 7.159 for UO+/U+ values in the range 7.68< UO+/U+
<8.17. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.2%.
OR433 (Maniobra Formation; Orocopia Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
157 ± 4 170 ± 55 99.9 98.7 - 241 507 7.86 (208Pb) 14-04 160 ± 3 158 ± 20 99.3 89.5 - 246 199 7.91 (208Pb) 14-13 163 ± 2 169 ± 13 100.0 100.0 - 921 664 7.87 (208Pb) 14-09 215 ± 3 247 ± 27 100.0 107.0 - 253 227 7.88 (208Pb) 14-16
1182 ± 27 1191 ± 18 99.9 99.2 1207 ± 24 195 173 7.86 (204Pb) 14-12 1552 ± 31 1580 ± 22 99.6 96.9 1617 ± 34 56 46 8.11 (204Pb) 14-03 1571 ± 23 1617 ± 13 99.9 99.0 1677 ± 9 1071 576 8.32 (204Pb) 14-02 1675 ± 54 1667 ± 27 99.7 97.4 1657 ± 36 78 45 7.74 (204Pb) 14-08 1681 ± 26 1674 ± 18 99.7 97.8 1666 ± 26 81 88 7.83 (204Pb) 14-06 1683 ± 26 1687 ± 19 99.7 97.3 1693 ± 25 149 66 7.87 (204Pb) 14-05 1728 ± 31 1695 ± 18 99.8 98.3 1655 ± 16 199 100 7.69 (204Pb) 14-10 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.862±0.029 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/15/2004: RSFPb/U = 1.519 x UO+/U+ - 7.159 for UO+/U+ values in the range 7.68< UO+/U+
<8.17. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.2%.
PP1 (Pigeon Point Formation; Pigeon Point) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
80 ± 5 91 ± 10 99.4 92.0 - 722 406 10.40 (208Pb) 10-18 92 ± 6 90 ± 17 98.2 75.5 - 157 97 9.76 (204Pb) 10-10 93 ± 7 109 ± 17 99.4 91.6 - 105 73 9.79 (208Pb) 10-15 95 ± 4 94 ± 12 98.2 75.8 - 235 139 9.36 (208Pb) 10-01 98 ± 5 108 ± 21 97.1 67.7 - 160 127 9.51 (208Pb) 10-07
100 ± 5 113 ± 19 97.0 67.6 - 182 118 9.46 (204Pb) 10-12 101 ± 10 89 ± 23 97.0 61.9 - 148 66 9.33 (208Pb) 10-03 106 ± 4 105 ± 7 99.0 84.6 - 710 202 9.43 (208Pb) 10-02 108 ± 7 105 ± 17 98.5 79.1 - 89 55 9.52 (208Pb) 10-06 108 ± 9 108 ± 30 97.1 65.6 - 75 45 9.95 (204Pb) 10-13 113 ± 6 134 ± 18 100.0 101.0 - 93 59 9.58 (208Pb) 10-05 119 ± 8 109 ± 21 97.9 71.1 - 124 158 10.00 (204Pb) 10-14
†Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.885±0.018 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 12/21/2001: RSFPb/U = 3.854 x UO+/U+ - 28.787 for UO+/U+ values in the range 8.46< UO+/U+
<9.33. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 6.7%.
PP2 (Pigeon Point Formation; Pigeon Point) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
95 ± 2 90 ± 11 98.5 77.9 - 116 46 9.44 (208Pb) 05-16 98 ± 3 114 ± 9 100.0 105.0 - 229 107 9.64 (208Pb) 05-04 99 ± 3 100 ± 11 98.8 82.8 - 254 85 9.59 (208Pb) 05-11 99 ± 2 109 ± 6 99.9 97.7 - 368 117 9.59 (208Pb) 05-05 99 ± 3 99 ± 8 98.8 82.5 - 224 99 9.84 (204Pb) 05-09
100 ± 2 96 ± 5 99.5 91.8 - 311 365 9.53 (204Pb) 05-12 101 ± 3 105 ± 8 99.7 95.7 - 468 207 9.89 (208Pb) 05-08 101 ± 2 110 ± 6 100.0 100.0 - 579 264 9.63 (208Pb) 05-15 110 ± 3 113 ± 15 98.9 83.9 - 76 26 9.76 (208Pb) 05-06 117 ± 2 125 ± 18 99.8 97.5 - 119 111 9.22 (208Pb) 05-01 125 ± 3 131 ± 22 98.3 78.3 - 63 36 9.69 (204Pb) 05-14 126 ± 5 133 ± 33 96.5 62.5 - 33 9 9.78 (208Pb) 05-07 138 ± 4 151 ± 26 98.9 85.4 - 60 47 9.70 (208Pb) 05-13 267 ± 8 253 ± 23 98.6 80.7 - 92 57 9.67 (204Pb) 05-10
†Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.941±0.030 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 12/25/2002: RSFPb/U = 2.027 x UO+/U+ - 11.750 for UO+/U+ values in the range 8.47< UO+/U+
<9.88. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 4.4%.
PP3 (Pigeon Point Formation; Pigeon Point) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
73 ± 4 74 ± 4 99.6 93.5 - 705 568 10.10 (204Pb) 04-06 85 ± 5 89 ± 13 98.0 73.9 - 143 60 9.72 (208Pb) 04-07 87 ± 5 91 ± 13 98.8 83.2 - 210 101 9.17 (208Pb) 04-05 88 ± 4 92 ± 10 99.5 92.4 - 372 202 9.55 (208Pb) 04-16 89 ± 3 88 ± 9 98.2 75.3 - 315 147 9.21 (208Pb) 04-09 90 ± 4 90 ± 14 98.4 78.4 - 247 125 9.27 (208Pb) 04-04 91 ± 3 92 ± 8 99.6 93.4 - 433 185 9.26 (208Pb) 04-10 92 ± 3 92 ± 8 99.4 89.8 - 534 292 9.23 (208Pb) 04-14 92 ± 6 93 ± 19 98.0 73.9 - 123 47 9.35 (208Pb) 04-17 95 ± 3 93 ± 8 98.8 81.7 - 469 170 9.08 (208Pb) 04-12 95 ± 4 99 ± 9 99.2 88.4 - 232 69 9.17 (204Pb) 04-11 97 ± 3 101 ± 6 99.8 97.1 - 465 115 9.12 (208Pb) 04-01
110 ± 7 111 ± 13 99.2 88.4 - 164 69 8.87 (204Pb) 04-02 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.885±0.018 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 12/21/2001: RSFPb/U = 3.854 x UO+/U+ - 28.787 for UO+/U+ values in the range 8.46< UO+/U+
<9.33. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 6.7%.
PS1 (Unnamed; Northwest Santa Lucia Range) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
92 ± 4 89 ± 17 95.3 53.0 - 245 132 9.40 (204Pb) 06-06 93 ± 4 93 ± 13 96.3 59.8 - 281 103 9.56 (208Pb) 06-14 96 ± 1 104 ± 7 98.8 83.1 - 581 92 9.81 (204Pb) 06-05 97 ± 2 91 ± 17 95.0 50.3 - 242 162 9.64 (208Pb) 06-10
103 ± 3 124 ± 30 92.2 45.1 - 116 49 9.66 (208Pb) 06-13 153 ± 6 136 ± 50 91.4 35.5 - 79 38 9.73 (208Pb) 06-17 158 ± 4 160 ± 34 94.4 50.0 - 149 191 9.78 (208Pb) 06-15 162 ± 8 154 ± 48 89.7 32.6 - 103 77 9.39 (208Pb) 06-11
281 ± 10 279 ± 37 98.1 75.9 - 148 47 9.49 (204Pb) 06-09 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 1.002±0.016 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 05/03/2002: RSFPb/U = 2.150 x UO+/U+ - 13.924 for UO+/U+ values in the range 9.64< UO+/U+
<9.98. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.9%.
PS2 (Pfeiffer slab; Point Sur) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
85 ± 1 83 ± 7 98.0 73.5 - 1369 307 8.73 (208Pb) 03-15 93 ± 2 90 ± 11 98.7 81.2 - 1233 722 8.61 (208Pb) 03-06 94 ± 1 99 ± 8 98.1 75.6 - 726 42 8.81 (208Pb) 03-20 95 ± 2 96 ± 20 96.8 63.3 - 301 213 8.82 (208Pb) 03-22 97 ± 2 90 ± 13 96.3 58.1 - 275 156 8.77 (208Pb) 03-17
120 ± 6 131 ± 31 91.2 39.5 - 77 47 8.82 (208Pb) 03-05 130 ± 5 131 ± 41 92.1 40.4 - 182 86 8.75 (208Pb) 03-09 150 ± 8 138 ± 70 87.1 26.6 - 52 17 8.37 (208Pb) 03-24
1156 ± 66 1238 ± 65 97.9 83.0 1383 ± 107 106 67 8.45 (204Pb) 03-12 1305 ± 72 1334 ± 47 99.4 94.5 1380 ± 64 453 55 8.78 (204Pb) 03-08 1314 ± 29 1357 ± 21 99.6 96.0 1424 ± 35 285 59 8.47 (204Pb) 03-19 1324 ± 16 1343 ± 11 99.8 97.9 1372 ± 17 427 232 8.88 (204Pb) 03-13 1353 ± 18 1365 ± 17 99.7 97.6 1384 ± 26 533 123 8.80 (204Pb) 03-03 1390 ± 21 1380 ± 13 99.8 98.2 1366 ± 24 478 71 8.83 (204Pb) 03-18 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.945±0.011 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 12/22/2002: RSFPb/U = 2.574 x UO+/U+ - 16.253 for UO+/U+ values in the range 8.51< UO+/U+
<9.34. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 4.0%.
PT1 (Unnamed; Northwest Santa Lucia Range) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
78 ± 5 64 ± 88 84.0 19.3 - 102 60 8.66 (208Pb) 04-18 79 ± 2 70 ± 15 96.3 56.6 - 357 358 8.85 (208Pb) 04-13 81 ± 5 55 ± 52 84.8 17.5 - 52 33 8.73 (208Pb) 04-07 83 ± 3 83 ± 20 95.8 56.5 - 191 193 8.89 (208Pb) 04-11 86 ± 2 85 ± 11 96.7 62.3 - 417 202 8.48 (208Pb) 04-05 90 ± 3 83 ± 20 88.1 27.9 - 223 154 8.65 (208Pb) 04-04 93 ± 1 92 ± 4 99.1 86.5 - 1400 163 8.80 (208Pb) 04-16 94 ± 2 91 ± 15 97.5 68.6 - 359 158 8.55 (208Pb) 04-12 95 ± 1 94 ± 11 98.2 75.5 - 663 212 8.85 (208Pb) 04-08 96 ± 3 95 ± 19 95.9 57.0 - 314 89 8.69 (208Pb) 04-06 99 ± 1 99 ± 4 99.0 84.6 - 995 382 8.71 (208Pb) 04-01
130 ± 3 132 ± 22 98.1 75.3 - 423 111 8.78 (208Pb) 04-10 142 ± 7 144 ± 45 93.4 45.4 - 86 40 8.59 (208Pb) 04-03
†Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.945±0.011 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 12/22/2002: RSFPb/U = 2.574 x UO+/U+ - 16.253 for UO+/U+ values in the range 8.51< UO+/U+
<9.34. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 4.0%.
PZ1 (Unnamed; La Panza Range) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
74 ± 2 68 ± 18 95.7 53.6 - 397 341 10.00 (204Pb) 08-18 75 ± 2 75 ± 17 95.5 54.8 - 511 258 10.10 (208Pb) 08-03 77 ± 1 74 ± 11 97.2 65.3 - 749 742 9.92 (204Pb) 08-02 78 ± 1 76 ± 10 97.1 65.2 - 500 204 9.94 (204Pb) 08-01 79 ± 4 87 ± 40 87.0 29.5 - 93 57 9.82 (208Pb) 08-07 79 ± 2 84 ± 16 95.5 56.4 - 404 142 9.67 (208Pb) 08-05 80 ± 2 87 ± 16 95.9 59.1 - 302 187 9.85 (204Pb) 08-06 84 ± 2 78 ± 14 95.8 54.5 - 399 271 9.70 (204Pb) 08-08
1799 ± 72 1743 ± 41 99.8 98.1 1675 ± 18 290 40 9.65 (204Pb) 08-04 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 1.002±0.016 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 05/03/2002: RSFPb/U = 2.150 x UO+/U+ - 13.924 for UO+/U+ values in the range 9.64< UO+/U+
<9.98. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.9%.
PZ3 (Unnamed; La Panza Range) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
67 ± 3 64 ± 10 98.9 83.4 - 298 148 9.54 (208Pb) 06-06 75 ± 3 74 ± 10 98.8 82.1 - 218 82 9.13 (208Pb) 06-05 78 ± 4 78 ± 8 98.6 79.9 - 433 231 9.09 (208Pb) 06-04
134 ± 6 134 ± 14 99.3 89.3 - 129 138 9.38 (204Pb) 06-14 157 ± 10 160 ± 27 98.5 79.7 - 78 85 9.19 (204Pb) 06-11 270 ± 13 269 ± 13 100.0 99.3 263 ± 47 405 283 8.80 (204Pb) 06-03 1407 ± 62 1401 ± 39 99.9 99.4 1393 ± 11 402 47 8.94 (204Pb) 06-15 1440 ± 61 1574 ± 39 99.9 99.6 1758 ± 13 155 60 9.72 (204Pb) 06-08 1503 ± 50 1567 ± 30 99.9 99.3 1653 ± 13 199 149 9.27 (204Pb) 06-01 1560 ± 41 1607 ± 24 100.0 99.8 1670 ± 7 1038 123 9.12 (204Pb) 06-07 1580 ± 59 1625 ± 36 100.0 99.8 1683 ± 9 531 64 9.17 (204Pb) 06-02 1657 ± 38 1705 ± 22 100.0 99.9 1764 ± 9 608 115 9.12 (204Pb) 06-13
1760 ± 141 1681 ± 74 100.0 99.7 1582 ± 11 441 141 8.62 (204Pb) 06-17 1844 ± 68 1782 ± 37 99.9 99.4 1710 ± 9 495 24 9.01 (204Pb) 06-10 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.885±0.018 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 12/21/2001: RSFPb/U = 3.854 x UO+/U+ - 28.787 for UO+/U+ values in the range 8.46< UO+/U+
<9.33. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 6.7%.
PZ4 (Unnamed; La Panza Range) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
76 ± 1 73 ± 11 96.1 57.6 - 321 140 10.80 (204Pb) 04-08 82 ± 5 137 ± 84 78.5 26.3 - 31 25 10.70 (204Pb) 04-04 82 ± 2 73 ± 20 93.7 42.8 - 260 225 9.48 (204Pb) 04-05 87 ± 3 77 ± 35 91.3 34.4 - 202 300 11.70 (204Pb) 04-12
245 ± 3 244 ± 8 99.3 90.2 240 ± 67 550 175 10.60 (204Pb) 04-06 1504 ± 17 1549 ± 10 99.9 99.4 1610 ± 9 867 69 10.30 (204Pb) 04-07 1647 ± 12 1656 ± 8 99.8 98.5 1669 ± 10 404 80 9.97 (204Pb) 04-02 1658 ± 23 1681 ± 19 98.7 90.5 1710 ± 32 114 65 10.60 (204Pb) 04-13 1684 ± 34 1683 ± 24 98.9 91.7 1680 ± 33 100 75 9.89 (204Pb) 04-11 1686 ± 25 1685 ± 16 99.8 98.4 1684 ± 13 311 124 10.80 (204Pb) 04-01 1726 ± 23 1727 ± 13 99.9 99.0 1729 ± 10 355 118 10.90 (204Pb) 04-10 1757 ± 40 1753 ± 22 99.8 98.7 1747 ± 27 577 302 12.30 (204Pb) 04-19 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 1.004±0.050 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 05/02/2002: RSFPb/U = 0.804 x UO+/U+ - 1.152 for UO+/U+ values in the range 9.04< UO+/U+
<10.60. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.3%.
SF1 (San Francisquito Formation; San Gabriel block) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
73 ± 2 70 ± 12 97.4 67.0 - 246 112 9.71 (208Pb) 10-02 74 ± 2 61 ± 31 82.2 17.8 - 243 166 10.10 (204Pb) 10-13 77 ± 1 74 ± 3 98.8 82.1 - 2286 1128 9.69 (204Pb) 11-02 83 ± 3 92 ± 22 96.6 64.6 - 124 177 9.52 (208Pb) 11-03
155 ± 3 160 ± 9 98.5 79.9 - 354 476 9.76 (204Pb) 10-15 159 ± 11 182 ± 111 89.0 35.4 - 20 22 9.67 (204Pb) 10-06 1297 ± 30 1354 ± 20 99.9 99.0 1444 ± 15 364 80 9.82 (204Pb) 12-05 1520 ± 30 1602 ± 26 97.9 85.3 1710 ± 34 164 58 9.89 (204Pb) 10-16 1654 ± 73 1674 ± 44 99.2 93.7 1699 ± 41 52 24 9.65 (204Pb) 11-05 1655 ± 39 1685 ± 23 99.7 97.4 1723 ± 21 126 37 9.30 (204Pb) 10-01 1667 ± 39 1702 ± 23 99.8 98.4 1746 ± 13 112 52 9.72 (204Pb) 10-05 1671 ± 36 1688 ± 22 99.9 99.3 1708 ± 24 623 112 9.83 (204Pb) 12-01 1673 ± 40 1701 ± 21 99.9 99.0 1735 ± 10 421 240 9.77 (204Pb) 10-07 1674 ± 27 1670 ± 15 99.9 99.6 1664 ± 7 2666 305 9.90 (204Pb) 10-14 1679 ± 37 1701 ± 23 99.8 98.3 1729 ± 15 321 81 10.00 (204Pb) 12-03 1681 ± 24 1709 ± 15 99.9 99.2 1743 ± 10 353 163 9.72 (204Pb) 11-07 1689 ± 26 1688 ± 15 99.9 99.3 1687 ± 7 2568 151 9.80 (204Pb) 10-17 1715 ± 28 1718 ± 15 99.8 98.3 1722 ± 15 258 126 9.57 (204Pb) 11-04 1723 ± 24 1699 ± 13 100.0 99.7 1670 ± 6 1291 32 9.57 (204Pb) 10-04 1787 ± 42 1754 ± 22 99.9 99.6 1715 ± 4 2283 501 9.88 (204Pb) 11-08 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.873±0.019 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 06/21/2001: RSFPb/U = 2.312 x UO+/U+ - 15.547 for UO+/U+ values in the range 8.46< UO+/U+
<9.33. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 3.1%.
SF2 (San Francisquito Formation; San Gabriel block) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
85 ± 1 96 ± 7 98.7 83.5 - 580 227 9.59 (208Pb) 08-11 1262 ± 23 1317 ± 16 99.9 99.3 1406 ± 10 273 20 9.76 (204Pb) 08-01 1540 ± 60 1594 ± 40 99.0 92.1 1667 ± 28 104 75 9.52 (204Pb) 06-14 1598 ± 29 1659 ± 17 99.9 99.2 1736 ± 11 322 30 9.85 (204Pb) 07-03 1615 ± 45 1650 ± 24 99.8 98.0 1696 ± 21 93 71 9.56 (204Pb) 06-01 1620 ± 28 1631 ± 16 99.8 98.4 1645 ± 17 268 25 9.60 (204Pb) 06-03 1620 ± 32 1668 ± 19 99.9 99.3 1729 ± 11 308 131 9.76 (204Pb) 06-05 1688 ± 37 1660 ± 20 99.9 99.1 1625 ± 16 615 200 9.77 (204Pb) 07-02 1693 ± 23 1699 ± 12 99.9 99.6 1706 ± 10 1105 64 9.81 (204Pb) 06-02 1695 ± 46 1709 ± 30 99.6 97.1 1727 ± 37 64 86 9.56 (204Pb) 06-04 1703 ± 37 1711 ± 20 99.6 97.2 1721 ± 21 284 97 9.50 (204Pb) 06-06 1707 ± 35 1716 ± 20 99.8 98.5 1727 ± 8 401 90 9.58 (204Pb) 07-01 1746 ± 24 1735 ± 13 99.9 99.1 1722 ± 11 338 73 9.50 (204Pb) 07-17 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.873±0.019 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 06/21/2001: RSFPb/U = 2.312 x UO+/U+ - 15.547 for UO+/U+ values in the range 8.46< UO+/U+
<9.33. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 3.1%.
SF3 (“San Francisquito Formation”; Cajon Pass) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
77 ± 2 82 ± 18 97.5 70.1 - 230 377 9.64 (208Pb) 04-02 77 ± 2 76 ± 11 98.7 80.8 - 479 434 9.97 (208Pb) 02-07 82 ± 2 86 ± 10 99.0 85.2 - 271 238 9.29 (208Pb) 02-04 90 ± 5 122 ± 66 61.4 11.1 - 296 236 9.67 (204Pb) 03-04
128 ± 7 120 ± 73 79.4 17.3 - 143 288 10.10 (208Pb) 03-03 140 ± 6 147 ± 19 98.0 75.3 - 115 97 9.65 (204Pb) 04-01 144 ± 4 130 ± 14 98.1 72.9 - 181 180 9.81 (204Pb) 02-12 145 ± 3 157 ± 22 96.5 63.5 - 209 125 9.81 (208Pb) 03-01 151 ± 4 153 ± 6 99.7 94.8 - 203 284 9.22 (204Pb) 02-02 153 ± 5 148 ± 23 97.4 67.8 - 121 113 9.68 (204Pb) 02-09 156 ± 3 160 ± 4 99.8 97.1 - 516 991 9.70 (204Pb) 02-10 159 ± 3 145 ± 13 98.3 75.3 - 191 304 9.86 (204Pb) 02-08 164 ± 3 178 ± 18 98.0 75.8 - 322 1135 9.61 (204Pb) 03-02
†Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.873±0.019 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 06/21/2001: RSFPb/U = 2.312 x UO+/U+ - 15.547 for UO+/U+ values in the range 8.46< UO+/U+
<9.33. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 3.1%.
SF4 (San Francisquito Formation; San Gabriel block) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
75 ± 2 83 ± 27 99.1 87.9 - 268 575 7.79 (208Pb) 07-07 148 ± 3 158 ± 23 99.3 89.6 - 220 255 8.24 (208Pb) 07-02 238 ± 6 238 ± 22 99.5 93.0 - 183 142 7.85 (208Pb) 07-06
1464 ± 11 1547 ± 7 100.0 99.7 1663 ± 7 757 193 7.72 (204Pb) 07-14 1482 ± 18 1530 ± 12 100.0 99.6 1597 ± 11 329 82 8.41 (204Pb) 07-09 1547 ± 18 1601 ± 13 100.0 99.8 1673 ± 12 1167 143 8.01 (204Pb) 07-03 1553 ± 17 1590 ± 11 100.0 99.8 1639 ± 14 483 165 8.06 (204Pb) 07-08 1613 ± 18 1640 ± 13 100.0 99.6 1675 ± 12 589 32 8.05 (204Pb) 07-19 1660 ± 21 1657 ± 10 99.9 99.4 1653 ± 11 257 125 7.78 (204Pb) 07-04 1677 ± 13 1676 ± 9 99.8 98.6 1675 ± 15 424 408 7.85 (204Pb) 07-10 1689 ± 76 1656 ± 47 99.2 93.4 1614 ± 62 23 17 8.08 (204Pb) 07-15 1702 ± 38 1659 ± 36 99.2 94.0 1605 ± 67 36 31 7.97 (204Pb) 07-01 1734 ± 25 1736 ± 15 99.9 99.2 1738 ± 13 320 168 7.92 (204Pb) 07-17 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.862±0.029 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/15/2004: RSFPb/U = 1.519 x UO+/U+ - 7.159 for UO+/U+ values in the range 7.68< UO+/U+
<8.17. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.2%.
SF5 (San Francisquito Formation; San Gabriel block) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
94 ± 2 103 ± 10 100.0 102.0 - 545 443 7.62 (208Pb) 08-11 155 ± 1 147 ± 13 99.6 93.1 - 1443 1071 7.83 (208Pb) 08-13 156 ± 3 145 ± 14 98.9 83.4 - 206 96 7.91 (208Pb) 08-12 205 ± 3 218 ± 13 99.7 95.2 - 176 74 8.02 (208Pb) 08-08
1162 ± 43 1152 ± 64 98.7 87.6 1131 ± 160 22 22 8.02 (204Pb) 08-04 1208 ± 35 1205 ± 29 99.7 97.3 1199 ± 45 100 47 7.94 (204Pb) 08-02 1209 ± 36 1197 ± 27 99.6 95.7 1176 ± 72 48 50 7.87 (204Pb) 08-07 1234 ± 24 1217 ± 23 99.7 97.1 1187 ± 42 79 67 7.87 (204Pb) 08-17 1394 ± 31 1395 ± 19 99.9 99.2 1397 ± 18 86 66 7.89 (204Pb) 08-10 1556 ± 19 1600 ± 11 99.9 99.5 1658 ± 15 172 45 8.18 (204Pb) 08-01 1605 ± 38 1635 ± 29 99.6 97.2 1674 ± 36 67 46 8.08 (204Pb) 08-09 1629 ± 17 1628 ± 17 99.7 97.7 1626 ± 25 156 61 7.96 (204Pb) 08-05 1696 ± 23 1703 ± 20 99.6 97.2 1713 ± 27 74 49 8.06 (204Pb) 08-03 1712 ± 36 1675 ± 22 99.5 96.4 1629 ± 31 59 49 7.89 (204Pb) 08-14 1776 ± 22 1761 ± 14 99.9 99.5 1744 ± 18 189 67 7.77 (204Pb) 08-16 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.862±0.029 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/15/2004: RSFPb/U = 1.519 x UO+/U+ - 7.159 for UO+/U+ values in the range 7.68< UO+/U+
<8.17. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.2%.
SH1 (Chatsworth Formation; Simi Hills) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
74 ± 4 53 ± 57 92.0 31.7 - 23 12 8.82 (208Pb) 10-06 75 ± 3 59 ± 13 97.4 62.5 - 161 48 7.24 (208Pb) 10-07 83 ± 2 98 ± 17 98.9 86.1 - 161 117 8.07 (208Pb) 10-13 85 ± 2 86 ± 21 97.3 67.3 - 67 24 8.04 (208Pb) 10-01 91 ± 1 100 ± 17 100.0 107.0 - 529 708 7.92 (208Pb) 10-11 92 ± 2 89 ± 13 98.7 81.2 - 135 72 7.82 (208Pb) 10-10 92 ± 1 90 ± 6 99.1 86.1 - 286 62 7.73 (208Pb) 10-12 99 ± 2 103 ± 13 98.9 84.2 - 186 82 8.11 (208Pb) 10-14
104 ± 2 88 ± 12 99.0 83.2 - 166 58 7.89 (208Pb) 10-05 106 ± 1 111 ± 6 99.9 99.0 - 647 323 7.88 (208Pb) 10-04 109 ± 2 136 ± 9 99.6 94.4 - 354 92 7.89 (208Pb) 10-02 109 ± 2 124 ± 14 101.0 111.0 - 798 794 7.96 (208Pb) 10-08 110 ± 2 123 ± 14 99.8 96.4 - 260 103 8.13 (208Pb) 10-15 112 ± 1 110 ± 9 99.7 94.6 - 438 137 7.93 (208Pb) 10-16 143 ± 2 149 ± 15 99.1 87.6 - 123 64 7.90 (208Pb) 10-03
†Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.862±0.029 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 03/15/2004: RSFPb/U = 1.519 x UO+/U+ - 7.159 for UO+/U+ values in the range 7.68< UO+/U+
<8.17. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.2%.
SH2 (Simi Conglomerate; Simi Hills) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
74 ± 1 78 ± 9 99.3 89.4 - 407 146 7.66 (208Pb) 11-06 79 ± 1 86 ± 7 100.0 103.0 - 722 424 7.90 (208Pb) 11-09
118 ± 2 109 ± 21 98.0 72.1 - 198 113 7.79 (208Pb) 11-12 151 ± 2 163 ± 12 99.8 96.9 - 230 148 8.04 (208Pb) 11-05
1094 ± 37 1212 ± 30 99.7 97.5 1430 ± 38 62 129 7.75 (204Pb) 11-07 1205 ± 26 1206 ± 32 99.7 96.7 1209 ± 61 54 31 8.07 (204Pb) 11-01 1564 ± 21 1573 ± 16 99.8 97.9 1585 ± 24 88 42 7.90 (204Pb) 11-08 1610 ± 27 1596 ± 16 99.9 99.0 1577 ± 20 247 85 7.64 (204Pb) 11-11 1658 ± 23 1665 ± 15 99.9 99.1 1674 ± 16 159 81 8.09 (204Pb) 11-04 1659 ± 26 1661 ± 16 99.9 99.1 1663 ± 18 158 73 7.97 (204Pb) 11-02 1671 ± 24 1682 ± 15 99.7 97.5 1696 ± 22 310 186 7.65 (204Pb) 11-10 1678 ± 25 1669 ± 16 99.7 97.3 1657 ± 17 177 61 7.97 (204Pb) 11-03 1707 ± 27 1691 ± 17 99.9 98.9 1670 ± 17 178 86 7.88 (204Pb) 11-14 1816 ± 28 1786 ± 19 99.9 99.3 1752 ± 18 346 158 7.86 (204Pb) 11-13 1846 ± 43 1850 ± 30 99.5 96.5 1855 ± 40 56 13 7.73 (204Pb) 11-15 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.862±0.029 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/15/2004: RSFPb/U = 1.519 x UO+/U+ - 7.159 for UO+/U+ values in the range 7.68< UO+/U+
<8.17. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.2%.
SM2 (Santa Susana Formation; Santa Monica Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
68 ± 2 70 ± 7 99.7 95.6 - 352 157 7.56 (208Pb) 07-16 68 ± 4 74 ± 13 99.0 85.3 - 143 78 7.78 (208Pb) 07-13 71 ± 1 73 ± 5 100.0 100.0 - 909 386 7.60 (208Pb) 07-14 71 ± 2 74 ± 4 100.0 101.0 - 1048 523 7.61 (208Pb) 07-17 75 ± 2 80 ± 8 99.6 93.4 - 176 59 7.63 (208Pb) 07-12 78 ± 1 81 ± 5 100.0 101.0 - 553 256 7.49 (208Pb) 07-15 81 ± 2 77 ± 6 99.6 92.5 - 336 173 7.55 (208Pb) 07-06 82 ± 2 82 ± 5 99.8 97.1 - 1383 626 7.57 (208Pb) 07-11 90 ± 3 93 ± 8 99.6 93.8 - 370 121 7.23 (208Pb) 07-02 96 ± 2 99 ± 6 99.9 98.4 - 665 502 7.54 (208Pb) 07-10
102 ± 3 106 ± 9 99.4 90.6 - 248 93 7.49 (208Pb) 07-05 110 ± 3 110 ± 7 99.8 96.4 - 707 225 7.31 (208Pb) 07-01 181 ± 6 194 ± 15 100.0 105.0 - 494 478 7.45 (208Pb) 07-04 181 ± 6 178 ± 15 100.0 99.3 - 320 262 7.53 (208Pb) 07-08
1694 ± 52 1669 ± 29 100.0 100.0 1637 ± 20 405 62 7.63 (208Pb) 07-03 1762 ± 60 1694 ± 31 99.8 98.3 1610 ± 20 179 106 7.32 (204Pb) 07-09 1814 ± 75 1770 ± 35 99.9 99.4 1719 ± 25 128 64 7.56 (204Pb) 07-07 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.871±0.014 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/18/2004: RSFPb/U = 2.310x UO+/U+ - 12.904 for UO+/U+ values in the range 6.97< UO+/U+
<8.05. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 7.0%.
SM3 (Chatsworth Formation; Santa Monica Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
74 ± 2 78 ± 5 99.9 97.7 - 610 322 7.60 (208Pb) 08-10 75 ± 2 74 ± 8 98.7 81.0 - 554 242 7.50 (208Pb) 08-18 78 ± 2 78 ± 8 99.9 97.7 - 569 262 7.51 (208Pb) 08-07 83 ± 2 79 ± 6 99.6 93.6 - 650 323 7.62 (208Pb) 08-03 85 ± 2 87 ± 5 100.0 100.0 - 901 435 7.53 (208Pb) 08-08 85 ± 3 92 ± 5 100.0 103.0 - 773 355 7.59 (208Pb) 08-16 85 ± 2 99 ± 6 101.0 108.0 - 700 402 7.32 (208Pb) 08-22 87 ± 2 83 ± 8 99.4 89.7 - 435 219 7.43 (208Pb) 08-13 87 ± 2 93 ± 4 100.0 104.0 - 544 257 7.52 (208Pb) 08-06 88 ± 2 80 ± 8 99.2 86.0 - 577 346 7.33 (208Pb) 08-02 92 ± 2 95 ± 5 100.0 100.0 - 1388 871 7.52 (208Pb) 08-15
103 ± 3 109 ± 6 100.0 103.0 - 352 146 7.66 (208Pb) 08-05 105 ± 5 107 ± 10 99.9 98.9 - 330 144 7.25 (208Pb) 08-21 107 ± 3 105 ± 5 99.6 93.8 - 749 270 7.55 (208Pb) 08-14 112 ± 3 109 ± 8 99.4 89.9 - 296 82 7.49 (208Pb) 08-04 131 ± 6 135 ± 15 99.0 85.5 - 227 100 7.20 (208Pb) 08-01
1485 ± 21 1510 ± 14 99.8 98.5 1546 ± 20 1123 112 7.43 (208Pb) 08-09 1537 ± 47 1566 ± 28 100.0 99.9 1606 ± 20 721 74 7.69 (204Pb) 08-11 1550 ± 28 1566 ± 17 100.0 99.9 1589 ± 25 747 13 7.38 (204Pb) 08-19 1642 ± 27 1656 ± 15 100.0 99.7 1673 ± 8 1048 53 7.51 (204Pb) 08-20 1772 ± 40 1751 ± 22 100.0 99.7 1726 ± 8 512 137 7.63 (204Pb) 08-12 1775 ± 53 1751 ± 29 99.8 98.6 1723 ± 18 225 112 7.52 (204Pb) 08-17 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.871±0.014 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/18/2004: RSFPb/U = 2.310x UO+/U+ - 12.904 for UO+/U+ values in the range 6.97< UO+/U+
<8.05. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 7.0%.
SM4 (Las Virgenes Sandstone; Area) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
102 ± 4 94 ± 12 99.2 87.1 - 226 136 7.81 (208Pb) 10-06 103 ± 3 97 ± 10 99.3 88.2 - 208 83 7.68 (208Pb) 10-07 104 ± 4 102 ± 9 99.5 91.8 - 256 118 7.63 (208Pb) 10-10 108 ± 3 115 ± 9 99.9 99.0 - 317 174 7.48 (208Pb) 10-15 111 ± 3 117 ± 12 99.9 98.2 - 176 72 7.59 (208Pb) 10-05 111 ± 5 120 ± 18 99.5 92.2 - 113 41 7.52 (208Pb) 10-12 113 ± 3 115 ± 8 99.6 93.7 - 223 45 7.39 (208Pb) 10-08 114 ± 4 117 ± 6 99.9 98.0 - 542 191 7.39 (208Pb) 10-11 117 ± 4 116 ± 4 99.9 98.0 - 1279 303 7.37 (208Pb) 10-02 119 ± 4 112 ± 15 99.1 85.5 - 151 58 7.29 (208Pb) 10-13 119 ± 4 128 ± 9 100.0 104.0 - 521 283 7.36 (208Pb) 10-09 121 ± 3 111 ± 8 99.2 86.7 - 327 128 7.37 (208Pb) 10-03 129 ± 5 129 ± 9 99.6 92.9 - 300 124 7.27 (208Pb) 10-04 131 ± 6 135 ± 11 99.9 97.7 - 360 183 7.24 (208Pb) 10-01 141 ± 8 136 ± 13 99.3 89.3 - 335 86 7.08 (208Pb) 10-14
†Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.871±0.014 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 03/18/2004: RSFPb/U = 2.310x UO+/U+ - 12.904 for UO+/U+ values in the range 6.97< UO+/U+
<8.05. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 7.0%.
SM6 (Llajas Formation; Santa Monica Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
73 ± 3 68 ± 12 99.0 84.1 - 236 156 7.35 (208Pb) 12-08 75 ± 4 79 ± 10 99.3 89.0 - 244 141 7.82 (208Pb) 12-01 81 ± 3 73 ± 9 98.4 75.8 - 172 43 7.40 (208Pb) 12-04 88 ± 4 87 ± 7 100.0 100.0 - 941 259 7.08 (208Pb) 12-13 89 ± 4 88 ± 6 100.0 99.5 - 576 88 7.24 (208Pb) 12-10
169 ± 4 175 ± 12 100.0 102.0 - 374 208 7.55 (208Pb) 12-03 1402 ± 39 1400 ± 30 99.9 99.1 1398 ± 41 179 144 7.55 (204Pb) 12-09 1470 ± 38 1444 ± 25 100.0 99.8 1405 ± 13 760 367 7.44 (204Pb) 12-07 1489 ± 42 1434 ± 27 99.6 96.4 1353 ± 29 204 136 7.52 (204Pb) 12-02 1601 ± 65 1620 ± 43 99.6 96.7 1644 ± 39 101 35 7.50 (204Pb) 12-12 1646 ± 58 1550 ± 30 99.9 99.0 1422 ± 17 207 136 7.24 (204Pb) 12-15 1680 ± 53 1661 ± 30 100.0 99.7 1636 ± 22 82 63 7.49 (204Pb) 12-06 1735 ± 80 1678 ± 46 99.8 98.1 1607 ± 35 117 66 7.54 (204Pb) 12-11 1771 ± 69 1743 ± 42 99.9 99.4 1710 ± 24 142 47 7.66 (204Pb) 12-14 1789 ± 59 1742 ± 32 99.7 97.8 1686 ± 26 116 44 7.37 (204Pb) 12-05 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.871±0.014 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/18/2004: RSFPb/U = 2.310x UO+/U+ - 12.904 for UO+/U+ values in the range 6.97< UO+/U+
<8.05. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 7.0%.
SM6A (Llajas Formation; Santa Monica Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
69 ± 3 71 ± 9 99.0 85.7 - 132 35 7.38 (208Pb) 14-06 73 ± 3 84 ± 12 100.0 99.6 - 155 91 7.39 (208Pb) 14-02 81 ± 5 107 ± 14 101.0 114.0 - 157 106 7.44 (208Pb) 14-07 85 ± 2 82 ± 6 99.6 93.3 - 676 246 7.42 (208Pb) 14-04 98 ± 3 111 ± 12 99.9 98.3 - 97 32 7.37 (208Pb) 14-12
119 ± 9 105 ± 15 98.8 80.7 - 211 74 7.04 (208Pb) 14-01 1004 ± 26 1129 ± 19 99.9 99.5 1379 ± 17 461 178 7.36 (204Pb) 14-10 1228 ± 54 1293 ± 40 99.9 98.8 1403 ± 30 160 56 7.55 (204Pb) 14-15 1316 ± 41 1332 ± 23 99.7 97.4 1357 ± 34 165 58 7.42 (204Pb) 14-13 1441 ± 27 1540 ± 19 100.0 99.9 1679 ± 14 383 33 7.36 (204Pb) 14-03 1479 ± 61 1555 ± 37 99.9 99.5 1659 ± 7 762 300 7.99 (204Pb) 14-11 1512 ± 42 1592 ± 30 100.0 99.6 1701 ± 21 207 104 7.55 (204Pb) 14-14 1523 ± 58 1573 ± 37 99.8 98.3 1640 ± 27 108 68 7.60 (204Pb) 14-08 1697 ± 50 1657 ± 31 99.3 94.1 1606 ± 23 232 121 7.37 (204Pb) 14-09 1800 ± 55 1762 ± 29 100.0 99.8 1717 ± 17 357 134 7.29 (204Pb) 14-05 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.871±0.014 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 03/18/2004: RSFPb/U = 2.310x UO+/U+ - 12.904 for UO+/U+ values in the range 6.97< UO+/U+
<8.05. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 7.0%.
SML1 (Unnamed; La Panza Range) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
72 ± 1 72 ± 7 98.9 83.9 - 267 141 9.25 (208Pb) 06-06 75 ± 1 71 ± 3 99.1 86.2 - 353 254 9.12 (204Pb) 06-08 78 ± 2 67 ± 13 98.4 74.5 - 72 34 9.06 (204Pb) 06-02 79 ± 1 77 ± 2 99.8 96.6 - 489 250 9.53 (204Pb) 06-21
232 ± 4 221 ± 9 99.1 85.9 - 201 130 9.37 (204Pb) 06-17 237 ± 4 229 ± 6 99.6 93.4 - 312 281 9.26 (204Pb) 06-18 239 ± 5 227 ± 6 99.9 97.6 - 122 113 9.10 (204Pb) 06-09 245 ± 8 235 ± 16 99.5 91.6 - 110 77 9.07 (204Pb) 06-04 268 ± 3 263 ± 5 99.9 98.2 222 ± 32 416 156 9.03 (204Pb) 06-13 510 ± 7 776 ± 9 99.9 99.5 1643 ± 12 413 261 8.97 (204Pb) 06-16
764 ± 13 796 ± 22 97.4 75.8 887 ± 70 191 69 8.98 (204Pb) 06-15 1297 ± 17 1387 ± 11 99.9 99.3 1529 ± 9 474 158 9.09 (204Pb) 06-01 1593 ± 32 1636 ± 24 99.9 99.6 1692 ± 39 290 176 9.01 (204Pb) 06-03 1714 ± 39 1729 ± 24 99.9 99.5 1746 ± 16 421 76 9.10 (204Pb) 06-05 2511 ± 37 2656 ± 15 100.0 99.8 2769 ± 7 166 71 9.11 (204Pb) 06-12 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.921±0.010 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 12/24/2002: RSFPb/U = 2.450 x UO+/U+ - 15.188 for UO+/U+ values in the range 8.47< UO+/U+
<9.34. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 3.2%.
TP1 (Buckhorn Sandstone; San Rafael Mountains) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
86 ± 3 84 ± 11 99.2 87.2 - 319 191 7.51 (208Pb) 15-19 87 ± 3 92 ± 6 100.0 101.0 - 819 356 7.48 (208Pb) 15-22 89 ± 3 89 ± 5 100.0 100.0 - 1187 445 7.75 (208Pb) 15-16 89 ± 2 90 ± 6 100.0 101.0 - 881 434 7.46 (208Pb) 15-18 90 ± 2 90 ± 3 99.8 97.2 - 1028 92 7.44 (208Pb) 15-20 93 ± 4 104 ± 15 97.9 75.2 - 227 139 7.47 (208Pb) 15-21 97 ± 2 99 ± 3 100.0 101.0 - 1209 297 7.50 (208Pb) 15-05 98 ± 2 95 ± 3 99.8 97.4 - 2372 309 7.39 (208Pb) 15-03 99 ± 3 103 ± 7 99.9 97.8 - 498 168 7.34 (208Pb) 15-24 99 ± 2 101 ± 7 100.0 102.0 - 598 296 7.41 (208Pb) 15-15
100 ± 2 100 ± 4 99.8 97.0 - 863 205 7.37 (208Pb) 15-23 100 ± 2 105 ± 6 100.0 101.0 - 853 549 7.48 (208Pb) 15-01 100 ± 3 95 ± 8 99.5 92.3 - 259 95 7.46 (208Pb) 15-06 103 ± 2 102 ± 5 100.0 99.2 - 1176 384 7.40 (208Pb) 15-02 105 ± 5 113 ± 20 99.2 88.1 - 442 231 7.18 (208Pb) 15-14 106 ± 3 109 ± 6 100.0 101.0 - 974 422 7.30 (208Pb) 15-04 106 ± 4 105 ± 8 99.5 92.2 - 504 291 7.22 (208Pb) 15-07 106 ± 4 111 ± 7 100.0 105.0 - 536 282 7.25 (208Pb) 15-11 113 ± 4 112 ± 5 100.0 101.0 - 1161 75 7.23 (208Pb) 15-25 114 ± 7 108 ± 10 99.7 94.5 - 478 189 7.08 (208Pb) 15-09 117 ± 7 132 ± 41 94.9 54.9 - 70 26 7.22 (208Pb) 15-17 125 ± 5 126 ± 6 99.7 95.2 - 597 29 7.32 (204Pb) 15-08 135 ± 6 145 ± 9 99.8 96.7 - 794 33 7.17 (204Pb) 15-12 152 ± 4 158 ± 9 100.0 103.0 - 570 342 7.38 (208Pb) 15-13 154 ± 5 166 ± 13 100.0 105.0 - 277 146 7.27 (208Pb) 15-10
†Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.871±0.014 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 03/18/2004: RSFPb/U = 2.310x UO+/U+ - 12.904 for UO+/U+ values in the range 6.97< UO+/U+
<8.05. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 7.0%.
VA1 (San Francisquito Formation; San Gabriel block) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
74 ± 1 67 ± 11 95.4 51.8 - 237 178 9.60 (204Pb) 03-09 74 ± 1 79 ± 13 95.7 57.2 - 181 91 9.71 (204Pb) 03-02 75 ± 2 75 ± 24 91.0 36.5 - 232 161 9.26 (204Pb) 03-12 76 ± 1 95 ± 12 96.3 64.9 - 214 159 9.68 (204Pb) 03-05
161 ± 2 163 ± 13 98.0 74.4 - 399 599 9.83 (204Pb) 03-14 1366 ± 9 1376 ± 6 99.9 99.1 1391 ± 7 716 17 9.32 (204Pb) 03-01 1643 ± 10 1660 ± 9 99.7 97.7 1682 ± 14 174 76 9.75 (204Pb) 03-04 1645 ± 17 1643 ± 19 98.4 88.0 1640 ± 34 55 44 9.68 (204Pb) 03-08 1659 ± 19 1667 ± 17 99.1 93.3 1676 ± 31 50 83 9.95 (204Pb) 03-10 1679 ± 13 1707 ± 8 99.8 98.4 1741 ± 12 161 62 9.98 (204Pb) 03-07 1691 ± 13 1685 ± 7 99.7 98.0 1677 ± 9 269 231 9.73 (204Pb) 03-13 1727 ± 15 1704 ± 12 99.7 98.0 1675 ± 18 229 94 9.58 (204Pb) 03-03 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 1.004±0.050 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 05/02/2002: RSFPb/U = 0.804 x UO+/U+ - 1.152 for UO+/U+ values in the range 9.04< UO+/U+
<10.60. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 1.3%.
YM1 (Atascadero Formation; Atascadero) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
64 ± 2 61 ± 6 95.7 54.1 - 1661 1251 9.32 (204Pb) 11-04 88 ± 3 90 ± 11 99.1 86.9 - 263 154 9.15 (208Pb) 11-05 91 ± 4 92 ± 9 97.2 66.6 - 491 156 8.95 (208Pb) 11-13 92 ± 3 91 ± 5 99.4 90.2 - 1121 493 9.36 (204Pb) 11-19 95 ± 4 90 ± 7 99.3 88.8 - 300 113 9.07 (204Pb) 11-16 95 ± 3 90 ± 8 98.7 81.0 - 499 224 9.07 (208Pb) 11-11 96 ± 3 96 ± 5 99.6 94.2 - 462 251 9.16 (204Pb) 11-15
106 ± 5 103 ± 13 99.4 90.4 - 165 85 9.32 (208Pb) 11-09 108 ± 3 105 ± 4 99.7 94.2 - 2715 910 9.10 (208Pb) 11-17 108 ± 7 103 ± 20 96.8 62.5 - 241 95 8.82 (208Pb) 11-02 113 ± 5 114 ± 12 99.2 88.1 - 175 62 9.07 (208Pb) 11-20 119 ± 5 124 ± 10 97.6 71.2 - 426 187 8.86 (208Pb) 11-14
237 ± 68 246 ± 65 98.4 79.3 - 197 47 8.05 (208Pb) 11-18 1627 ± 74 1650 ± 42 99.8 98.7 1679 ± 13 209 120 8.90 (204Pb) 11-01 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.885±0.018 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 12/21/2001: RSFPb/U = 3.854 x UO+/U+ - 28.787 for UO+/U+ values in the range 8.46< UO+/U+
<9.33. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 6.7%.
YM2 (Atascadero Formation; Atascadero) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
94 ± 1 91 ± 8 97.3 66.9 - 713 195 8.99 (208Pb) 06-08 96 ± 1 92 ± 13 97.4 67.2 - 753 336 8.78 (208Pb) 06-10 98 ± 2 92 ± 29 91.4 36.2 - 270 122 8.72 (208Pb) 06-09 98 ± 2 90 ± 16 96.7 60.6 - 476 249 8.82 (208Pb) 06-04
100 ± 1 105 ± 10 97.4 69.4 - 426 161 8.83 (208Pb) 06-15 103 ± 2 114 ± 25 94.8 53.7 - 320 220 8.73 (208Pb) 06-05 104 ± 4 103 ± 29 92.3 40.5 - 140 54 8.61 (208Pb) 06-14 146 ± 3 145 ± 15 97.9 73.5 - 473 194 8.74 (208Pb) 06-13
1014 ± 22 1028 ± 22 98.8 88.4 1056 ± 43 325 63 8.92 (204Pb) 06-16 1091 ± 56 1041 ± 77 96.4 69.1 936 ± 222 40 17 8.91 (204Pb) 06-07 1403 ± 26 1380 ± 28 99.0 91.4 1345 ± 55 122 75 8.75 (204Pb) 06-12 1634 ± 58 1672 ± 53 97.4 82.2 1720 ± 99 25 27 9.19 (204Pb) 06-18 1694 ± 24 1731 ± 15 99.6 96.9 1777 ± 19 352 111 8.91 (204Pb) 06-17 1949 ± 76 1890 ± 61 97.7 85.0 1826 ± 93 61 102 8.63 (204Pb) 06-11 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.945±0.011 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 12/22/2002: RSFPb/U = 2.574 x UO+/U+ - 16.253 for UO+/U+ values in the range 8.51< UO+/U+
<9.34. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 4.0%.
YM3 (Atascadero Formation; Atascadero) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
80 ± 2 84 ± 18 94.9 53.0 - 298 265 9.64 (208Pb) 09-26 84 ± 2 90 ± 10 98.1 75.8 - 613 254 9.40 (208Pb) 09-10 92 ± 2 93 ± 8 98.2 76.2 - 508 275 9.49 (208Pb) 09-23 92 ± 2 95 ± 11 98.1 75.0 - 780 422 9.49 (208Pb) 09-29 95 ± 3 107 ± 21 95.9 60.4 - 220 224 9.49 (208Pb) 09-28 98 ± 2 102 ± 15 95.4 55.5 - 236 77 9.33 (208Pb) 09-33
111 ± 3 121 ± 19 95.6 58.0 - 190 98 9.71 (208Pb) 09-02 112 ± 2 108 ± 14 97.0 64.0 - 350 155 9.25 (208Pb) 09-16 113 ± 3 124 ± 12 97.8 74.2 - 281 177 9.31 (208Pb) 09-09 113 ± 5 84 ± 31 93.8 38.8 - 164 54 9.46 (208Pb) 09-38 114 ± 4 115 ± 55 91.1 37.2 - 102 50 9.30 (208Pb) 09-19 116 ± 2 115 ± 20 95.9 57.2 - 226 142 9.38 (208Pb) 09-34 118 ± 3 120 ± 26 95.0 52.9 - 152 61 9.36 (208Pb) 09-07
†Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.945±0.011 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 12/22/2002: RSFPb/U = 2.574 x UO+/U+ - 16.253 for UO+/U+ values in the range 8.51< UO+/U+
<9.34. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 4.0%.
YM4 – Part 1 (Atascadero Formation; Atascadero) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
85 ± 3 81 ± 10 97.8 71.2 - 390 206 8.87 (208Pb) 10-27 96 ± 3 97 ± 20 94.8 51.5 - 138 46 8.66 (208Pb) 10-01 98 ± 5 106 ± 15 95.8 58.6 - 180 98 8.93 (208Pb) 10-20
106 ± 4 109 ± 38 91.1 37.5 - 66 26 9.33 (208Pb) 10-24 109 ± 4 105 ± 15 96.8 62.3 - 142 67 9.02 (208Pb) 10-13 113 ± 3 112 ± 19 98.1 74.3 - 263 123 8.96 (208Pb) 10-06 125 ± 5 129 ± 12 98.6 81.1 - 553 341 9.32 (208Pb) 10-22 140 ± 5 145 ± 14 97.1 67.0 - 165 67 8.98 (208Pb) 10-04 141 ± 4 151 ± 21 95.7 58.1 - 130 55 8.94 (208Pb) 10-07 142 ± 8 144 ± 16 98.1 75.8 - 110 34 8.76 (208Pb) 10-03 144 ± 4 137 ± 25 96.9 63.0 - 166 79 8.81 (208Pb) 10-14 147 ± 3 147 ± 20 96.4 61.3 - 144 61 9.23 (208Pb) 10-05 152 ± 6 154 ± 24 98.4 78.2 - 110 52 8.83 (204Pb) 10-10 156 ± 5 163 ± 20 95.8 58.4 - 88 32 8.77 (208Pb) 10-11 276 ± 4 366 ± 10 98.4 84.3 980 ± 58 342 118 8.96 (204Pb) 10-08
1018 ± 36 1042 ± 23 99.4 93.7 1094 ± 39 308 146 9.32 (204Pb) 10-16 †Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.955±0.015 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 ##Session 12/24/2002: RSFPb/U = 2.460 x UO+/U+ - 15.253 for UO+/U+ values in the range 8.46< UO+/U+
<9.33. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 2.7%.
YM4 – Part 2 (Atascadero Formation; Atascadero) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge§
± 1σ (Ma)
U#
(ppm)
Th††
(ppm)
UO+/U+
Pb Corr.§§
Analysis ID##
93 ± 4 78 ± 11 97.4 64.1 - 518 260 8.95 (208Pb) 10 103 ± 5 99 ± 32 94.7 49.7 - 89 38 8.98 (208Pb) 06 106 ± 4 109 ± 4 99.9 98.2 - 1520 788 8.91 (208Pb) 02 107 ± 4 98 ± 15 97.7 68.8 - 294 91 8.98 (208Pb) 08 108 ± 4 111 ± 18 98.6 80.3 - 132 95 9.11 (208Pb) 03 109 ± 4 121 ± 11 99.2 88.5 - 328 151 8.97 (208Pb) 05 116 ± 6 88 ± 34 95.1 45.6 - 152 91 8.97 (208Pb) 07 116 ± 4 115 ± 9 99.0 84.8 - 385 177 9.13 (208Pb) 04 120 ± 5 122 ± 13 95.6 56.2 - 169 89 9.01 (208Pb) 01 123 ± 5 120 ± 22 97.3 67.2 - 184 84 8.93 (208Pb) 09
†Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Italics indicate that 207Pb/206Pb age was used instead of 206Pb/238U age in calculating probability functions
and plotting pie diagrams. #Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. ††Calculated from measured Th+/U+: RSFTh/U = 0.924 §§Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.86; 207Pb/204Pb = 15.62; 208Pb/204Pb = 38.34 ##Session 12/23/2005: RSFPb/U = 2.334 x UO+/U+ - 14.333 for UO+/U+ values in the range 8.46< UO+/U+
<9.28. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 2.6%.
YM5 (Atascadero Formation; Atascadero) 206Pb/238U
Age† ± 1σ (Ma)
207Pb/235U Age†
± 1σ (Ma)
206Pb*
(%)
207Pb*
(%)
207Pb/206PbAge
± 1σ (Ma)
U§
(ppm)
Th#
(ppm)
UO+/U+
Pb Corr.††
Analysis ID§§
88 ± 2 90 ± 9 98.0 74.0 - 426 182 9.31 (208Pb) 11-02 89 ± 2 92 ± 16 97.0 65.4 - 372 173 9.37 (208Pb) 11-08 93 ± 2 99 ± 15 98.0 74.5 - 409 227 9.49 (208Pb) 11-09 94 ± 2 87 ± 8 98.5 78.2 - 493 214 8.96 (208Pb) 11-12 97 ± 3 98 ± 13 97.2 67.0 - 212 71 8.84 (204Pb) 11-18 99 ± 3 98 ± 6 99.0 84.7 - 693 305 8.92 (204Pb) 11-15
103 ± 3 114 ± 45 92.1 42.5 - 96 46 9.43 (208Pb) 11-07 107 ± 3 114 ± 19 98.0 74.7 - 129 68 8.92 (204Pb) 11-19 108 ± 6 80 ± 34 92.7 34.7 - 95 52 8.49 (208Pb) 11-10 112 ± 5 128 ± 26 95.6 59.0 - 170 46 9.36 (208Pb) 11-06 126 ± 7 143 ± 20 96.1 61.9 - 121 66 8.83 (208Pb) 11-11 132 ± 3 124 ± 15 97.4 67.4 - 122 53 9.08 (208Pb) 11-17 143 ± 5 132 ± 24 93.9 45.2 - 77 23 9.55 (208Pb) 11-01 176 ± 5 165 ± 14 99.0 84.2 - 411 262 8.74 (208Pb) 11-14
†Analytical precision only. Reflects counting errors and does not include calibration uncertainties. §Calculated from measured U+/94Zr2O+. Assumes a mean U-content of 550 ppm in AS-3 std. zircon. #Calculated from measured Th+/U+: RSFTh/U = 0.955±0.015 ††Radiogenic Pb calculated using either 204Pb or 208Pb as a proxy for common Pb. Assumed composition of
common Pb is 206Pb/204Pb = 18.7; 207Pb/204Pb = 15.6; 208Pb/204Pb = 37.9 §§Session 12/24/2002: RSFPb/U = 2.460 x UO+/U+ - 15.253 for UO+/U+ values in the range 8.46< UO+/U+
<9.33. Assumes AS-3 std. Zircon is 1099 Ma. Calibration scatter defined by AS-3 std. zircon 206Pb/238U age results was ± 2.7%.
Zircon U-Pb Data Tables
Forearc Sedimentary Units Analyzed with University of Arizona LA-ICPMS
LP21 (Jalama(?) Formation; Santa Ynez Mountains)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
LP21-55 926 8203 1.4 0.0745 2.5 0.0108 1.7 0.69 69.0 1.2 73.0 1.8 205.2 42.6 69.0 1.2LP21-53 3109 23062 3.7 0.0709 1.6 0.0108 1.2 0.71 69.3 0.8 69.5 1.1 75.7 27.1 69.3 0.8LP21-64 714 4378 1.4 0.0789 5.7 0.0111 4.2 0.74 71.0 3.0 77.1 4.2 271.5 87.3 71.0 3.0LP21-51 512 3187 1.5 0.0752 5.5 0.0112 3.8 0.70 72.1 2.8 73.7 3.9 125.4 91.5 72.1 2.8LP21-13 483 2672 1.9 0.0834 9.9 0.0114 4.5 0.46 73.2 3.3 81.3 7.7 327.7 199.9 73.2 3.3LP21-02 873 5927 1.5 0.0747 5.3 0.0114 2.3 0.43 73.3 1.7 73.2 3.7 66.9 113.8 73.3 1.7LP21-73 627 5164 1.6 0.0800 4.7 0.0114 2.3 0.48 73.4 1.6 78.2 3.5 228.3 95.1 73.4 1.6LP21-68 250 2152 0.9 0.0667 8.4 0.0115 3.1 0.37 73.8 2.2 65.6 5.3 -225.5 196.8 73.8 2.2LP21-23 802 4381 1.2 0.0788 3.4 0.0116 2.3 0.66 74.3 1.7 77.0 2.5 162.5 59.8 74.3 1.7LP21-30 736 4633 1.2 0.0790 5.8 0.0116 3.2 0.56 74.3 2.4 77.2 4.3 168.6 111.0 74.3 2.4LP21-15 901 6070 1.3 0.0796 7.6 0.0117 3.7 0.49 74.9 2.8 77.7 5.7 166.7 154.0 74.9 2.8LP21-56 652 3244 1.2 0.0883 4.7 0.0118 2.5 0.54 75.9 1.9 85.9 3.8 373.4 88.5 75.9 1.9LP21-43 317 3223 2.4 0.0794 9.9 0.0119 3.3 0.33 76.0 2.5 77.6 7.4 126.7 220.7 76.0 2.5LP21-03 409 2133 0.8 0.0859 8.3 0.0120 4.0 0.48 76.8 3.0 83.7 6.6 283.9 165.8 76.8 3.0LP21-17 728 3122 1.5 0.0954 15.9 0.0123 3.4 0.21 78.7 2.6 92.5 14.1 465.4 347.3 78.7 2.6LP21-69 639 9060 5.2 0.0863 3.6 0.0123 1.0 0.29 79.0 0.8 84.1 2.9 229.4 80.0 79.0 0.8LP21-37 1091 11354 1.9 0.0864 2.5 0.0124 1.7 0.68 79.1 1.3 84.1 2.0 228.3 41.6 79.1 1.3LP21-14 873 5920 1.0 0.0900 3.6 0.0126 2.0 0.56 80.9 1.6 87.5 3.0 272.5 68.1 80.9 1.6LP21-06 630 4793 1.7 0.0830 9.4 0.0128 8.8 0.94 82.1 7.2 80.9 7.3 46.6 76.8 82.1 7.2LP21-54 569 2184 1.3 0.0862 6.7 0.0129 1.7 0.26 82.4 1.4 84.0 5.4 130.0 152.3 82.4 1.4LP21-24 656 5256 1.5 0.0903 4.2 0.0130 2.4 0.56 83.0 1.9 87.8 3.5 221.7 80.6 83.0 1.9LP21-01 624 5226 1.2 0.0901 8.1 0.0131 4.4 0.54 84.0 3.7 87.6 6.8 186.6 158.7 84.0 3.7LP21-75 539 4254 0.9 0.0891 4.8 0.0132 2.6 0.53 84.5 2.2 86.7 4.0 147.7 95.6 84.5 2.2LP21-72 445 2379 1.2 0.0976 8.3 0.0134 2.5 0.31 85.8 2.2 94.6 7.5 320.8 179.7 85.8 2.2LP21-04 1107 8690 1.2 0.0899 6.8 0.0135 2.8 0.41 86.2 2.4 87.4 5.7 120.1 145.5 86.2 2.4LP21-67 357 3787 1.4 0.0916 6.6 0.0135 2.0 0.30 86.6 1.7 89.0 5.6 153.3 147.3 86.6 1.7LP21-63 155 1757 3.0 0.0681 24.6 0.0139 4.6 0.19 88.8 4.0 66.9 15.9 -662.4 673.4 88.8 4.0LP21-07 462 2052 1.1 0.1035 12.2 0.0139 3.6 0.29 88.8 3.2 100.0 11.6 376.2 263.6 88.8 3.2LP21-11 1528 11821 2.8 0.0910 3.2 0.0140 1.9 0.60 89.9 1.7 88.4 2.7 49.1 61.5 89.9 1.7LP21-42 693 6838 11.8 0.1007 2.5 0.0141 1.3 0.52 90.1 1.2 97.4 2.4 279.3 49.7 90.1 1.2LP21-66 109 2160 1.5 0.0848 24.5 0.0142 7.9 0.32 91.2 7.1 82.7 19.5 -158.1 583.3 91.2 7.1LP21-19 251 2317 0.8 0.0919 7.0 0.0148 3.9 0.55 95.0 3.6 89.2 6.0 -61.1 142.5 95.0 3.6LP21-41 273 2898 0.7 0.0780 12.1 0.0149 2.1 0.17 95.4 2.0 76.3 8.9 -488.2 317.8 95.4 2.0LP21-08 872 7600 1.0 0.1061 2.5 0.0150 1.5 0.58 96.1 1.4 102.4 2.5 251.1 47.4 96.1 1.4LP21-61 390 3213 1.6 0.1109 9.8 0.0151 2.3 0.24 96.4 2.2 106.8 10.0 343.9 216.9 96.4 2.2
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
LP21-60 656 6941 4.6 0.1103 5.4 0.0153 3.3 0.61 98.0 3.2 106.3 5.5 296.0 97.9 98.0 3.2LP21-22 744 6395 2.6 0.1025 4.9 0.0154 2.2 0.44 98.4 2.1 99.1 4.7 115.9 104.6 98.4 2.1LP21-10 173 1497 1.3 0.0888 10.8 0.0156 5.7 0.53 99.7 5.7 86.4 9.0 -266.3 233.7 99.7 5.7LP21-05 903 8739 2.0 0.1114 3.2 0.0159 1.8 0.55 101.6 1.8 107.2 3.2 234.1 61.6 101.6 1.8LP21-48 512 5288 1.7 0.1143 4.7 0.0159 2.5 0.53 101.7 2.5 109.9 4.8 291.4 90.1 101.7 2.5LP21-32 346 3934 2.9 0.1112 6.4 0.0159 3.2 0.51 101.8 3.3 107.1 6.5 226.2 127.1 101.8 3.3LP21-46 175 2092 1.2 0.1079 11.3 0.0163 4.2 0.38 104.0 4.4 104.1 11.1 105.3 246.9 104.0 4.4LP21-20 221 1792 2.9 0.1069 7.7 0.0164 2.5 0.32 104.7 2.6 103.1 7.5 66.1 173.5 104.7 2.6LP21-38 183 2533 2.7 0.1276 9.1 0.0181 5.9 0.64 115.9 6.8 121.9 10.5 240.0 161.7 115.9 6.8LP21-57 384 3808 2.2 0.1379 6.9 0.0193 5.5 0.79 123.5 6.7 131.2 8.5 272.7 95.6 123.5 6.7LP21-27 178 3260 0.5 0.1847 6.0 0.0244 2.9 0.48 155.7 4.4 172.1 9.5 404.3 118.3 155.7 4.4LP21-12 339 8074 2.2 0.2301 4.2 0.0317 2.9 0.68 201.4 5.7 210.3 8.0 311.1 70.2 201.4 5.7LP21-47 226 11607 1.1 1.9632 1.8 0.1832 1.4 0.77 1084.3 13.9 1103.0 12.1 1140.0 22.7 1140.0 22.7LP21-65 480 19880 4.4 1.9230 7.6 0.1779 6.6 0.86 1055.3 63.9 1089.1 51.1 1157.3 77.6 1157.3 77.6LP21-26 396 47697 1.5 2.7778 4.8 0.2255 4.6 0.98 1311.1 55.1 1349.6 35.5 1411.1 20.1 1411.1 20.1LP21-18 213 26196 0.6 2.9206 2.2 0.2368 1.5 0.71 1369.8 19.0 1387.3 16.4 1414.2 29.3 1414.2 29.3LP21-50 130 17531 1.2 2.8993 2.1 0.2333 1.7 0.79 1351.9 20.6 1381.7 16.0 1428.1 24.7 1428.1 24.7LP21-45A 278 36668 0.4 3.1646 5.2 0.2461 4.4 0.86 1418.4 56.2 1448.6 39.8 1493.1 50.5 1493.1 50.5LP21-21 150 5247 0.6 3.4123 3.7 0.2534 2.7 0.73 1456.0 35.3 1507.2 29.1 1579.9 47.3 1579.9 47.3LP21-74 537 88861 1.9 4.1792 2.6 0.2998 2.0 0.76 1690.1 29.1 1670.0 21.0 1644.7 30.8 1644.7 30.8LP21-52 522 69941 3.5 4.0757 2.1 0.2838 1.6 0.76 1610.5 22.5 1649.5 16.9 1699.4 24.7 1699.4 24.7LP21-33 419 28791 5.3 4.1303 3.2 0.2848 2.0 0.61 1615.3 28.1 1660.3 26.4 1717.8 47.1 1717.8 47.1LP21-29 586 82246 5.9 4.4358 5.4 0.3058 4.2 0.78 1720.0 63.5 1719.0 44.6 1717.8 61.6 1717.8 61.6LP21-16 210 38239 2.1 4.5416 3.9 0.3126 3.2 0.83 1753.5 49.5 1738.6 32.2 1720.7 39.4 1720.7 39.4LP21-31 193 43879 1.3 4.3297 3.8 0.2945 2.3 0.61 1663.8 33.9 1699.0 31.4 1742.8 55.4 1742.8 55.4LP21-70 451 66562 2.6 4.1692 5.0 0.2831 4.4 0.89 1607.0 63.0 1668.0 40.8 1745.6 41.6 1745.6 41.6LP21-39 818 144158 6.7 4.4666 1.8 0.3026 1.4 0.76 1704.0 20.4 1724.8 14.8 1750.1 21.2 1750.1 21.2LP21-36 185 29839 1.4 4.3563 1.9 0.2936 1.4 0.72 1659.7 20.4 1704.1 15.9 1759.1 24.4 1759.1 24.4LP21-71 306 55093 1.6 4.8108 2.3 0.3238 1.7 0.76 1808.5 27.2 1786.8 19.0 1761.5 26.7 1761.5 26.7LP21-35 726 75199 1.6 4.4557 1.8 0.2972 1.5 0.79 1677.3 21.5 1722.8 15.3 1778.5 20.4 1778.5 20.4LP21-34 925 135921 5.6 4.3682 3.4 0.2912 2.9 0.85 1647.6 41.9 1706.3 28.1 1779.2 32.8 1779.2 32.8LP21-45 821 97182 3.4 4.6759 5.6 0.3093 4.1 0.73 1737.4 61.9 1762.9 46.7 1793.3 69.6 1793.3 69.6LP21-40 358 71475 1.9 4.5556 4.2 0.3012 4.0 0.94 1697.1 59.2 1741.2 35.3 1794.5 26.8 1794.5 26.8LP21-62 596 87532 3.3 4.4798 3.5 0.2955 2.2 0.64 1669.0 32.4 1727.2 28.7 1798.5 48.4 1798.5 48.4LP21-44 399 65994 2.3 4.7903 2.1 0.3150 1.2 0.57 1765.0 18.7 1783.2 17.9 1804.5 32.0 1804.5 32.0LP21-59 418 53531 1.1 4.8258 3.6 0.3171 2.3 0.63 1775.6 35.6 1789.4 30.4 1805.5 51.0 1805.5 51.0LP21-49 734 114982 2.3 5.2853 1.8 0.3321 1.1 0.61 1848.7 18.1 1866.5 15.7 1886.3 26.1 1886.3 26.1
OR432 (Maniobra Formation; Orocopia Mountains)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
OR432-36 486 1902 2.0 0.0790 4.6 0.0120 1.7 0.37 77.0 1.3 77.2 3.4 83.3 102.3 77.0 1.3OR432-38 274 1615 0.7 0.1599 5.7 0.0240 2.4 0.42 153.2 3.7 150.7 8.0 111.0 122.9 153.2 3.7OR432-9 117 852 1.1 0.1328 27.0 0.0241 2.7 0.10 153.8 4.2 126.6 32.2 -359.0 705.9 153.8 4.2OR432-13 283 3340 0.5 0.1628 3.4 0.0243 1.7 0.49 155.0 2.6 153.2 4.9 125.9 70.4 155.0 2.6OR432-35 638 5287 0.5 0.1675 6.9 0.0245 3.2 0.47 156.0 5.0 157.3 10.1 176.1 142.5 156.0 5.0OR432-45 172 848 1.0 0.1593 15.0 0.0247 3.0 0.20 157.5 4.6 150.1 20.9 34.7 353.2 157.5 4.6OR432-39 383 1834 0.8 0.1640 6.3 0.0249 3.7 0.59 158.7 5.8 154.2 9.0 86.1 121.3 158.7 5.8OR432-20 604 3947 1.2 0.1664 3.9 0.0251 1.7 0.43 159.7 2.6 156.3 5.7 104.3 84.0 159.7 2.6OR432-31 609 3156 0.8 0.1680 4.5 0.0251 1.0 0.22 159.8 1.6 157.7 6.5 125.8 102.6 159.8 1.6OR432-28 556 3877 1.1 0.1712 2.5 0.0254 1.1 0.42 161.4 1.7 160.5 3.7 146.8 53.2 161.4 1.7OR432-2 255 9822 1.2 0.1827 3.9 0.0256 1.7 0.44 162.7 2.8 170.4 6.2 277.7 80.7 162.7 2.8OR432-1 558 12323 1.0 0.1844 2.4 0.0259 1.4 0.58 164.6 2.3 171.9 3.8 272.3 45.5 164.6 2.3OR432-23 349 1883 0.9 0.1691 9.5 0.0263 4.0 0.42 167.1 6.6 158.7 13.9 34.2 205.8 167.1 6.6OR432-18 438 5366 1.1 0.2249 4.9 0.0331 1.8 0.38 210.1 3.8 206.0 9.1 159.5 105.9 210.1 3.8OR432-41 614 5863 2.3 0.2523 4.5 0.0362 2.4 0.53 228.9 5.4 228.5 9.2 223.5 88.0 228.9 5.4OR432-27 2139 38474 7.6 1.6555 6.1 0.1661 5.8 0.94 990.5 52.8 991.7 38.9 994.3 43.5 994.3 43.5OR432-6 70 6676 1.0 2.0830 2.8 0.1921 1.9 0.67 1132.7 19.4 1143.2 19.2 1163.2 41.2 1163.2 41.2OR432-33 37 3802 1.3 2.1747 3.7 0.1970 2.3 0.61 1159.0 24.1 1173.0 26.0 1198.9 58.5 1198.9 58.5OR432-48 119 2367 1.4 2.5758 2.8 0.2171 1.5 0.54 1266.5 17.7 1293.8 20.8 1339.4 46.1 1339.4 46.1OR432-25 220 2036 1.1 2.7612 5.7 0.2324 2.6 0.46 1347.1 31.9 1345.1 42.5 1342.0 97.7 1347.1 31.9OR432-5 679 124533 1.6 2.8414 2.4 0.2303 2.2 0.90 1336.0 26.4 1366.5 18.3 1414.6 20.5 1414.6 20.5OR432-4 464 106536 1.7 2.9040 2.6 0.2350 2.4 0.92 1360.8 29.5 1382.9 19.7 1417.2 19.1 1417.2 19.1OR432-24 400 29274 1.5 3.4726 6.1 0.2685 4.5 0.75 1533.3 61.9 1521.0 48.0 1504.0 76.6 1504.0 76.6OR432-49 147 23663 1.3 3.5512 2.7 0.2690 1.6 0.58 1535.9 21.2 1538.7 21.1 1542.6 40.7 1542.6 40.7OR432-44 280 2349 1.8 3.4579 3.0 0.2592 2.1 0.71 1485.5 28.2 1517.7 23.7 1562.8 40.0 1562.8 40.0OR432-29 413 16793 3.4 3.1636 6.4 0.2353 5.2 0.80 1362.0 63.3 1448.3 49.7 1577.3 72.1 1577.3 72.1OR432-19 137 9801 1.4 3.8920 3.8 0.2811 3.2 0.85 1597.0 45.4 1612.0 30.4 1631.6 36.8 1631.6 36.8OR432-3 574 38240 2.0 3.8974 2.2 0.2783 1.9 0.88 1582.7 27.0 1613.1 17.7 1653.0 19.5 1653.0 19.5OR432-17 355 9944 1.6 3.8257 4.3 0.2721 2.8 0.66 1551.6 39.1 1598.2 34.6 1660.1 59.8 1660.1 59.8OR432-12 281 46369 1.9 3.9424 2.7 0.2789 1.7 0.61 1585.8 23.2 1622.4 21.9 1670.3 39.4 1670.3 39.4OR432-46 287 11783 1.7 4.0681 2.2 0.2875 2.0 0.89 1629.1 28.4 1647.9 18.1 1672.1 18.7 1672.1 18.7OR432-26 1449 26479 1.1 4.1304 1.8 0.2919 1.4 0.81 1651.0 20.9 1660.3 14.4 1672.2 18.9 1672.2 18.9OR432-22 1016 33503 1.9 3.9450 3.2 0.2785 2.3 0.71 1583.7 32.2 1623.0 26.1 1674.2 41.8 1674.2 41.8OR432-11 270 48817 1.5 4.0232 2.5 0.2836 1.3 0.52 1609.5 18.8 1638.9 20.6 1676.7 39.9 1676.7 39.9OR432-8 2461 115199 1.1 4.1533 2.5 0.2919 2.1 0.85 1651.1 30.3 1664.9 20.1 1682.2 24.0 1682.2 24.0OR432-50 891 60550 12.6 4.1815 3.2 0.2933 1.5 0.45 1658.2 21.3 1670.4 26.6 1685.7 53.5 1685.7 53.5
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
OR432-14 123 12926 1.4 4.1786 3.3 0.2916 3.0 0.89 1649.5 43.4 1669.8 27.4 1695.4 27.7 1695.4 27.7OR432-34 1268 82038 2.4 4.2320 2.4 0.2943 2.2 0.89 1663.1 31.7 1680.2 20.0 1701.8 20.6 1701.8 20.6OR432-30 144 12522 0.6 4.2537 2.0 0.2956 1.7 0.84 1669.7 24.5 1684.4 16.3 1702.9 19.7 1702.9 19.7OR432-16 601 28456 1.8 4.1977 4.1 0.2916 1.9 0.46 1649.4 27.5 1673.6 34.0 1704.0 67.8 1704.0 67.8OR432-37 171 22442 0.8 4.2848 2.8 0.2951 2.5 0.89 1667.2 36.9 1690.4 23.1 1719.4 23.3 1719.4 23.3OR432-40 744 68431 2.4 4.2970 1.6 0.2947 1.1 0.66 1664.8 15.4 1692.8 13.2 1727.6 22.2 1727.6 22.2OR432-7 305 63251 2.6 4.2251 2.3 0.2891 1.0 0.43 1637.1 14.5 1678.9 19.3 1731.6 38.9 1731.6 38.9OR432-10 457 42077 2.0 4.0696 1.7 0.2779 1.1 0.69 1580.6 16.1 1648.2 13.6 1735.5 22.2 1735.5 22.2OR432-47 357 20847 2.8 4.7016 2.6 0.3150 1.9 0.73 1765.5 28.8 1767.5 21.4 1769.9 31.9 1769.9 31.9OR432-43 217 24807 1.9 4.5839 3.2 0.3063 1.2 0.37 1722.5 18.1 1746.3 26.9 1775.0 54.7 1775.0 54.7OR432-32 254 36127 2.4 12.4974 2.2 0.4930 1.6 0.73 2583.6 34.3 2642.5 20.8 2688.0 25.1 2688.0 25.1
OR433 (Maniobra Formation; Orocopia Mountains)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
OR433-44 2157 447 1.2 0.1213 16.3 0.0211 5.0 0.31 134.8 6.7 116.3 17.9 -248.3 393.9 134.8 6.7OR433-4 94 738 2.0 0.1526 12.5 0.0235 4.5 0.36 150.1 6.6 144.2 16.8 49.3 279.5 150.1 6.6OR433-38 188 4063 0.7 0.1657 5.6 0.0239 1.1 0.20 152.4 1.7 155.6 8.1 204.7 127.5 152.4 1.7OR433-50 677 899 0.4 0.1452 12.4 0.0240 2.5 0.20 153.1 3.7 137.6 16.0 -121.2 301.6 153.1 3.7OR433-40 730 2235 1.3 0.1617 4.8 0.0244 2.1 0.45 155.7 3.3 152.2 6.8 99.1 101.2 155.7 3.3OR433-11 196 977 0.9 0.1568 18.8 0.0248 3.4 0.18 158.2 5.3 147.9 25.8 -13.8 449.4 158.2 5.3OR433-32 146 1087 0.5 0.1566 9.6 0.0249 2.7 0.28 158.6 4.2 147.8 13.2 -22.3 223.0 158.6 4.2OR433-1 615 3699 0.9 0.1707 2.5 0.0253 1.0 0.39 160.8 1.6 160.0 3.7 149.2 54.5 160.8 1.6OR433-14 432 1326 0.5 0.1776 21.3 0.0265 7.1 0.34 168.5 11.9 166.0 32.6 130.6 476.2 168.5 11.9OR433-2 303 252 810.0 0.1805 9.0 0.0280 1.9 0.22 178.0 3.4 168.5 14.0 36.5 211.0 178.0 3.4OR433-46 2002 3329 2.1 0.2171 3.2 0.0319 1.9 0.59 202.5 3.7 199.5 5.8 163.7 60.7 202.5 3.7OR433-45 100 4716 3.0 1.9661 2.8 0.1862 2.0 0.73 1100.6 20.5 1104.0 18.6 1110.5 37.5 1110.5 37.5OR433-49 84 1558 1.2 2.5384 11.2 0.2243 10.0 0.90 1304.7 118.2 1283.1 81.6 1247.2 97.6 1247.2 97.6OR433-12 393 27999 1.7 2.9328 3.4 0.2422 2.5 0.74 1398.0 31.4 1390.4 25.5 1378.8 43.5 1378.8 43.5OR433-48 416 9312 1.5 2.8872 5.9 0.2376 2.1 0.35 1374.3 25.9 1378.6 44.9 1385.2 107.1 1374.3 25.9OR433-15 294 23220 2.3 2.9193 4.5 0.2389 1.7 0.37 1381.2 20.8 1386.9 33.9 1395.7 79.7 1381.2 20.8OR433-34 541 54641 1.6 3.3445 2.5 0.2595 1.7 0.69 1487.3 23.0 1491.5 19.5 1497.5 34.1 1497.5 34.1OR433-28 286 7227 2.3 3.4897 5.0 0.2693 4.2 0.84 1537.4 57.4 1524.9 39.6 1507.6 51.8 1507.6 51.8OR433-37 1239 60094 23.7 3.3074 3.7 0.2493 3.1 0.82 1434.6 39.3 1482.8 29.1 1552.4 40.2 1552.4 40.2OR433-36 380 21259 2.2 3.4755 3.8 0.2587 2.8 0.72 1482.9 36.8 1521.7 30.2 1576.0 49.4 1576.0 49.4OR433-22 1890 1593 1.4 1.6781 2.5 0.1244 1.7 0.69 756.1 12.3 1000.3 15.8 1582.7 33.5 1582.7 33.5OR433-10 2694 22352 3.5 3.6140 3.5 0.2671 3.0 0.84 1526.3 40.3 1552.6 28.2 1588.6 36.1 1588.6 36.1OR433-42 2297 5578 7.3 3.4197 3.5 0.2522 1.9 0.54 1449.9 24.7 1508.9 27.8 1592.8 55.8 1592.8 55.8OR433-39 63 6469 2.2 3.6478 2.3 0.2647 1.0 0.43 1513.7 13.5 1560.0 18.5 1623.3 38.9 1623.3 38.9OR433-17 800 52363 3.1 3.9326 4.0 0.2843 2.3 0.57 1613.0 32.4 1620.4 32.3 1630.0 61.0 1630.0 61.0OR433-29 317 21430 1.0 3.9681 3.0 0.2861 2.4 0.78 1621.9 33.9 1627.7 24.6 1635.1 35.2 1635.1 35.2OR433-21 469 35178 1.4 4.0426 2.7 0.2910 1.0 0.36 1646.4 14.5 1642.8 22.3 1638.3 47.4 1638.3 47.4OR433-30 341 26721 2.1 3.8554 4.2 0.2767 1.5 0.36 1574.5 21.3 1604.4 34.0 1643.8 73.0 1643.8 73.0OR433-41 163 13967 4.5 4.1021 1.9 0.2919 1.4 0.73 1651.0 20.3 1654.7 15.7 1659.4 24.4 1659.4 24.4OR433-47 950 54555 1.5 4.1705 3.4 0.2967 2.4 0.72 1674.9 35.7 1668.2 27.5 1659.8 43.2 1659.8 43.2OR433-9 2332 60909 2.6 4.0530 2.0 0.2861 1.3 0.67 1622.1 19.0 1644.9 16.0 1674.1 27.0 1674.1 27.0OR433-26 384 16107 3.1 4.1771 4.4 0.2948 3.4 0.77 1665.7 49.5 1669.5 36.0 1674.4 51.9 1674.4 51.9OR433-31 324 22998 3.9 4.0867 3.4 0.2884 2.7 0.81 1633.4 39.3 1651.6 27.4 1674.9 36.1 1674.9 36.1OR433-33 201 54088 1.4 4.1659 3.2 0.2939 2.2 0.69 1661.2 32.0 1667.3 26.1 1675.0 42.9 1675.0 42.9OR433-24 351 17447 2.1 4.2805 5.2 0.3003 3.5 0.67 1692.6 52.4 1689.6 43.2 1685.9 71.9 1685.9 71.9OR433-23 416 33138 1.8 4.1792 3.1 0.2930 2.0 0.65 1656.7 29.7 1669.9 25.6 1686.6 43.8 1686.6 43.8
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
OR433-20 234 4816 2.0 4.1492 3.9 0.2884 3.1 0.80 1633.6 44.9 1664.1 31.9 1702.6 43.5 1702.6 43.5OR433-18 353 24398 2.0 4.4051 3.2 0.3044 2.1 0.66 1713.0 32.0 1713.3 26.6 1713.6 44.2 1713.6 44.2OR433-7 344 23868 2.8 4.2834 3.2 0.2958 2.8 0.89 1670.4 41.9 1690.2 26.3 1714.8 26.4 1714.8 26.4OR433-43 127 11258 1.7 4.4587 2.4 0.3061 1.7 0.68 1721.5 25.1 1723.3 20.2 1725.5 32.6 1725.5 32.6OR433-19 723 52747 9.6 4.2973 4.8 0.2921 3.7 0.79 1652.1 54.6 1692.8 39.2 1743.7 53.5 1743.7 53.5OR433-5 160 18882 1.6 4.5512 2.9 0.3091 1.8 0.62 1736.4 27.1 1740.4 23.9 1745.1 41.4 1745.1 41.4OR433-16 420 41981 2.2 4.5251 2.9 0.3069 1.7 0.60 1725.4 26.1 1735.6 24.0 1747.8 42.5 1747.8 42.5OR433-35 136 13851 1.2 4.6121 5.8 0.3117 2.3 0.39 1749.3 34.7 1751.5 48.1 1754.0 96.9 1754.0 96.9OR433-25 717 76066 9.7 4.8399 8.6 0.3259 6.0 0.70 1818.3 95.7 1791.9 72.4 1761.3 111.6 1761.3 111.6OR433-8 2091 79811 1.6 4.6307 4.1 0.3078 1.1 0.28 1730.1 17.2 1754.8 33.9 1784.4 70.9 1784.4 70.9OR433-6 189 16578 1.8 4.7890 7.2 0.3169 2.7 0.37 1774.7 41.3 1783.0 60.7 1792.6 122.2 1792.6 122.2OR433-27 435 29568 2.0 5.5300 3.0 0.3427 2.4 0.81 1899.8 40.2 1905.3 26.0 1911.2 31.8 1911.2 31.8
SH6 (Llajas Formation; Simi Hills)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
SH6-38 203 1507 2.6 0.0576 10.7 0.0111 4.4 0.41 71.3 3.1 56.8 5.9 -517.5 260.8 71.3 3.1SH6-19 591 2981 6.3 0.0663 5.7 0.0112 4.0 0.70 72.1 2.9 65.2 3.6 -180.9 102.2 72.1 2.9SH6-37 172 1417 3.7 0.0492 17.8 0.0114 5.2 0.29 73.2 3.8 48.7 8.5 -1038.5 512.5 73.2 3.8SH6-6 1025 7312 2.2 0.0723 3.8 0.0117 2.3 0.61 75.2 1.7 70.9 2.6 -71.9 73.3 75.2 1.7SH6-26 441 4949 1.7 0.1007 4.0 0.0147 2.8 0.71 94.0 2.6 97.4 3.7 182.7 64.8 94.0 2.6SH6-23 1134 9393 1.4 0.0945 2.6 0.0147 1.8 0.69 94.3 1.7 91.6 2.3 22.3 44.9 94.3 1.7SH6-54 220 1438 1.4 0.0690 19.1 0.0156 2.1 0.11 100.0 2.1 67.7 12.5 -965.3 561.3 100.0 2.1SH6-7 1757 2594 1.5 0.1729 8.5 0.0233 7.8 0.92 148.4 11.5 162.0 12.8 364.5 76.6 148.4 11.5SH6-35 513 11713 0.9 0.1806 6.3 0.0248 5.7 0.91 158.0 9.0 168.6 9.8 319.1 60.0 158.0 9.0SH6-8 271 3912 1.3 0.1630 5.0 0.0251 2.3 0.47 159.8 3.7 153.3 7.1 54.7 104.7 159.8 3.7SH6-17 551 8901 1.0 0.1873 6.7 0.0258 4.4 0.65 164.2 7.1 174.3 10.8 313.8 116.6 164.2 7.1SH6-53 173 3083 0.8 0.1485 6.1 0.0260 2.1 0.34 165.2 3.4 140.6 8.0 -258.3 145.5 165.2 3.4SH6-27 497 6063 2.3 0.1783 3.6 0.0260 2.5 0.67 165.4 4.0 166.6 5.6 183.5 62.5 165.4 4.0SH6-22 372 5900 1.3 0.1803 3.5 0.0260 1.9 0.56 165.7 3.2 168.4 5.4 206.5 66.6 165.7 3.2SH6-48 514 11310 1.1 0.1842 3.6 0.0262 2.5 0.70 166.5 4.1 171.7 5.6 242.9 58.8 166.5 4.1SH6-42 486 5780 0.5 0.1849 6.3 0.0262 5.3 0.84 167.0 8.8 172.3 10.0 245.0 77.9 167.0 8.8SH6-40 317 5386 1.7 0.1816 5.8 0.0263 2.9 0.50 167.5 4.8 169.4 9.1 197.2 117.0 167.5 4.8SH6-57 608 9504 1.0 0.1705 2.2 0.0265 1.8 0.80 168.3 3.0 159.8 3.3 35.5 32.1 168.3 3.0SH6-20 1069 9023 1.3 0.1785 3.3 0.0265 2.1 0.62 168.7 3.5 166.8 5.1 139.9 61.3 168.7 3.5SH6-55 325 5225 1.0 0.1837 4.6 0.0265 1.9 0.42 168.8 3.2 171.2 7.3 205.6 97.8 168.8 3.2SH6-58 212 2326 2.2 0.1698 7.2 0.0269 4.5 0.62 171.0 7.5 159.3 10.7 -11.6 137.5 171.0 7.5SH6-31 485 7982 0.7 0.1961 4.4 0.0272 2.3 0.53 173.2 3.9 181.8 7.3 295.6 84.4 173.2 3.9SH6-39 121 1285 1.4 0.1802 9.5 0.0273 4.3 0.46 173.6 7.4 168.2 14.7 94.1 199.1 173.6 7.4SH6-46 319 4938 1.2 0.1931 4.5 0.0274 2.3 0.51 174.4 4.0 179.3 7.4 243.5 89.8 174.4 4.0SH6-47 323 7463 1.3 0.1835 3.7 0.0274 3.0 0.82 174.5 5.2 171.1 5.8 124.0 48.8 174.5 5.2SH6-33 373 3044 1.4 0.2117 6.7 0.0278 3.8 0.56 177.0 6.6 194.9 11.9 418.4 123.7 177.0 6.6SH6-29 174 5546 1.4 0.2383 3.3 0.0345 1.8 0.54 218.4 3.9 217.0 6.5 202.1 65.2 218.4 3.9SH6-2 767 75965 8.3 2.7676 2.9 0.2281 2.3 0.79 1324.4 27.3 1346.8 21.6 1382.7 34.4 1382.7 34.4SH6-60 607 116730 2.2 3.0618 3.0 0.2506 2.0 0.67 1441.5 25.9 1423.2 22.9 1395.8 42.6 1395.8 42.6SH-14 220 26422 1.1 3.0381 3.7 0.2482 2.3 0.63 1429.1 30.1 1417.2 28.6 1399.4 55.8 1399.4 55.8SH6-56 583 98670 2.8 2.8090 3.6 0.2275 2.7 0.75 1321.3 32.0 1358.0 26.7 1416.1 45.1 1416.1 45.1SH6-1 307 52584 1.8 2.9706 3.6 0.2395 3.1 0.87 1384.2 38.9 1400.1 27.3 1424.5 34.0 1424.5 34.0SH-13 121 9762 1.8 3.0675 2.6 0.2472 1.9 0.72 1424.1 24.1 1424.6 20.1 1425.4 34.8 1425.4 34.8SH6-3 205 16385 1.3 3.0181 3.0 0.2432 2.1 0.70 1403.2 26.7 1412.2 23.1 1425.8 41.4 1425.8 41.4SH6-25 270 42899 1.7 3.1714 2.3 0.2540 1.6 0.68 1458.9 20.7 1450.2 18.0 1437.5 32.5 1437.5 32.5
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
SH6-16 250 28848 1.9 3.1424 2.8 0.2505 2.5 0.89 1441.2 31.7 1443.1 21.2 1446.1 23.8 1446.1 23.8SH6-34 215 22924 4.6 3.3090 3.7 0.2615 2.9 0.79 1497.6 39.3 1483.2 29.1 1462.6 43.6 1462.6 43.6SH-12 371 49456 2.5 3.4111 5.0 0.2692 4.7 0.94 1536.6 64.3 1507.0 39.2 1465.5 31.6 1465.5 31.6SH6-32 279 45709 3.5 2.9629 5.2 0.2321 5.0 0.95 1345.4 60.1 1398.2 39.6 1479.5 31.0 1479.5 31.0SH6-21 849 85509 3.7 3.1992 3.8 0.2473 3.1 0.82 1424.7 39.6 1457.0 29.2 1504.2 40.6 1504.2 40.6SH-11 355 54837 4.7 4.3847 2.1 0.3105 1.6 0.74 1743.3 23.8 1709.5 17.3 1668.3 25.9 1668.3 25.9SH-15 68 8681 0.9 4.2098 2.7 0.2972 1.7 0.64 1677.5 25.8 1675.9 22.4 1674.0 38.8 1674.0 38.8SH6-41 247 41646 0.8 4.1411 5.8 0.2886 5.2 0.90 1634.6 75.6 1662.5 47.6 1697.9 46.5 1697.9 46.5SH6-24 175 36986 1.5 4.4269 2.4 0.3065 1.7 0.73 1723.3 26.1 1717.4 19.7 1710.1 30.0 1710.1 30.0SH6-52 439 24316 5.1 4.0093 5.4 0.2769 5.0 0.92 1575.6 69.8 1636.1 44.2 1714.8 39.2 1714.8 39.2SH6-59 660 81198 5.6 4.2828 3.1 0.2944 2.4 0.78 1663.7 35.1 1690.1 25.2 1722.9 35.1 1722.9 35.1SH6-5 116 7018 1.1 4.3579 3.7 0.2996 2.7 0.73 1689.2 40.2 1704.4 30.8 1723.1 47.1 1723.1 47.1SH6-51 197 42881 1.6 4.6038 2.3 0.3143 1.6 0.70 1761.8 24.7 1749.9 19.2 1735.8 30.3 1735.8 30.3SH6-49 782 45448 7.5 4.8388 3.9 0.3282 2.8 0.73 1829.8 45.0 1791.7 32.7 1747.5 48.7 1747.5 48.7SH6-9 626 52755 1.8 4.5593 3.3 0.3070 2.8 0.84 1726.0 41.9 1741.9 27.6 1760.9 33.3 1760.9 33.3SH6-28 273 39847 1.2 4.7833 3.8 0.3209 3.7 0.95 1794.3 57.5 1782.0 32.3 1767.5 21.1 1767.5 21.1SH6-30 238 50585 3.4 4.6765 4.8 0.3116 2.7 0.55 1748.6 40.7 1763.0 40.1 1780.2 72.8 1780.2 72.8SH6-50 148 14419 2.2 4.9703 4.1 0.3241 1.3 0.32 1809.6 20.9 1814.3 34.9 1819.7 70.9 1819.7 70.9
SH7 (Chatsworth Formation; Simi Hills)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
SH7-24 645 1353 0.9 0.1034 14.3 0.0123 3.3 0.23 78.7 2.6 99.9 13.6 639.4 301.2 78.7 2.6SH7-43 325 2332 1.1 0.0848 6.0 0.0124 3.1 0.51 79.5 2.4 82.7 4.7 177.2 119.3 79.5 2.4SH7-15 410 2991 1.5 0.0817 8.5 0.0124 5.0 0.59 79.7 4.0 79.8 6.5 82.0 161.5 79.7 4.0SH7-42 2456 8822 6.0 0.0891 4.9 0.0128 4.2 0.87 82.1 3.4 86.7 4.0 215.5 56.1 82.1 3.4SH7-39 393 3041 1.5 0.0867 8.1 0.0130 3.5 0.43 83.0 2.9 84.5 6.6 126.6 173.0 83.0 2.9SH7-54 465 5434 2.3 0.0905 5.4 0.0130 4.0 0.73 83.4 3.3 87.9 4.6 213.2 86.0 83.4 3.3SH7-18 352 2235 1.0 0.0864 8.7 0.0130 4.6 0.53 83.4 3.8 84.2 7.0 106.7 174.9 83.4 3.8SH7-35 560 5328 1.8 0.0918 4.8 0.0130 3.0 0.62 83.5 2.5 89.2 4.1 244.5 85.8 83.5 2.5SH7-58 622 4115 1.3 0.0883 7.4 0.0132 4.9 0.65 84.4 4.1 85.9 6.1 127.1 132.7 84.4 4.1SH7-11 575 5043 1.6 0.0912 4.4 0.0132 2.1 0.48 84.6 1.8 88.6 3.8 196.5 90.3 84.6 1.8SH7-62 498 4577 3.2 0.0964 3.5 0.0135 2.8 0.79 86.6 2.4 93.4 3.1 270.3 49.9 86.6 2.4SH7-19 348 2995 1.6 0.0837 7.1 0.0136 3.6 0.50 86.9 3.1 81.7 5.6 -69.9 149.6 86.9 3.1SH7-57 431 2517 1.5 0.0932 7.5 0.0137 2.7 0.35 87.4 2.3 90.4 6.5 170.7 165.1 87.4 2.3SH7-23 556 6289 3.0 0.0951 4.5 0.0140 1.8 0.39 89.4 1.6 92.2 4.0 165.3 97.3 89.4 1.6SH7-30 689 4941 2.9 0.1044 6.2 0.0142 2.7 0.44 90.8 2.5 100.9 6.0 346.4 126.3 90.8 2.5SH7-40 350 2653 2.0 0.1044 9.4 0.0144 2.6 0.28 92.4 2.4 100.8 9.0 306.2 204.8 92.4 2.4SH7-37 686 7586 1.7 0.1046 5.1 0.0146 2.1 0.42 93.6 2.0 101.0 4.9 278.8 105.5 93.6 2.0SH7-22 745 6393 1.7 0.1018 3.7 0.0147 1.7 0.46 94.1 1.6 98.4 3.5 205.5 76.4 94.1 1.6SH7-51 565 5704 3.0 0.1019 3.3 0.0148 1.8 0.54 94.5 1.7 98.6 3.1 196.5 63.5 94.5 1.7SH7-16 622 2145 2.9 0.1100 5.6 0.0149 1.9 0.33 95.4 1.8 106.0 5.6 350.5 119.7 95.4 1.8SH7-45 578 5082 2.1 0.1018 5.6 0.0149 3.1 0.55 95.5 2.9 98.4 5.2 169.7 108.8 95.5 2.9SH7-25 879 7361 2.6 0.1073 3.2 0.0151 2.3 0.71 96.5 2.2 103.5 3.2 268.4 52.6 96.5 2.2SH7-69 248 2905 3.0 0.1045 7.7 0.0151 3.2 0.41 96.7 3.0 100.9 7.4 201.2 163.8 96.7 3.0SH7-08 559 9560 6.1 0.1077 4.3 0.0151 3.1 0.71 96.8 3.0 103.8 4.2 268.6 69.1 96.8 3.0SH7-01 1009 9518 2.0 0.1084 4.8 0.0152 2.7 0.55 97.3 2.6 104.5 4.8 270.3 92.1 97.3 2.6SH7-14 606 3550 1.7 0.1077 5.5 0.0153 4.5 0.82 98.1 4.4 103.9 5.4 238.9 72.6 98.1 4.4SH7-64 691 8606 3.0 0.1070 3.1 0.0154 1.4 0.46 98.3 1.4 103.2 3.1 219.7 64.4 98.3 1.4SH7-04 799 8198 2.1 0.1072 4.3 0.0155 2.8 0.64 99.2 2.7 103.4 4.3 203.0 77.7 99.2 2.7SH7-13 927 8519 2.2 0.1072 2.9 0.0155 2.2 0.76 99.2 2.1 103.4 2.8 202.6 43.5 99.2 2.1SH7-10 957 8669 2.2 0.1087 3.6 0.0156 2.3 0.64 99.5 2.3 104.8 3.6 227.0 64.7 99.5 2.3SH7-38 636 5282 2.5 0.1124 6.0 0.0157 4.1 0.68 100.1 4.1 108.2 6.2 289.5 101.0 100.1 4.1SH7-61 1353 10479 0.9 0.1009 2.3 0.0157 1.8 0.78 100.1 1.8 97.6 2.2 37.2 34.6 100.1 1.8SH7-12 408 2671 3.5 0.1222 24.5 0.0157 2.0 0.08 100.4 2.0 117.1 27.1 471.5 547.1 100.4 2.0SH7-65 561 6975 3.2 0.1092 3.2 0.0158 1.7 0.54 100.9 1.7 105.2 3.2 205.4 63.0 100.9 1.7SH7-73 502 4693 2.6 0.1054 5.3 0.0158 1.8 0.34 101.0 1.8 101.7 5.2 118.0 118.6 101.0 1.8SH7-74 1357 11042 2.1 0.1035 2.8 0.0158 2.5 0.89 101.2 2.5 100.0 2.7 70.7 29.9 101.2 2.5
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
SH7-71 1074 7054 2.0 0.1093 5.3 0.0159 4.3 0.80 101.8 4.3 105.3 5.3 185.6 74.6 101.8 4.3SH7-66 1574 10996 2.9 0.1029 4.1 0.0159 2.9 0.69 101.8 2.9 99.4 3.9 41.5 72.0 101.8 2.9SH7-50 719 9941 3.0 0.1096 4.0 0.0159 1.9 0.49 101.9 1.9 105.6 4.0 189.5 80.4 101.9 1.9SH7-68 1665 16724 2.4 0.1094 6.6 0.0160 4.1 0.63 102.1 4.2 105.4 6.6 180.6 118.7 102.1 4.2SH7-72 562 5949 2.9 0.1072 3.9 0.0160 2.7 0.69 102.2 2.7 103.4 3.8 131.8 65.6 102.2 2.7SH7-60 984 9989 2.5 0.1139 2.7 0.0160 2.2 0.81 102.3 2.2 109.5 2.8 270.5 36.2 102.3 2.2SH7-67 771 8018 2.1 0.1116 4.5 0.0161 2.9 0.64 102.9 3.0 107.4 4.6 210.3 80.4 102.9 3.0SH7-49 239 2469 2.4 0.1050 6.1 0.0161 3.2 0.53 102.9 3.3 101.4 5.9 66.3 122.9 102.9 3.3SH7-48 548 5696 3.1 0.1219 3.5 0.0162 2.0 0.58 103.9 2.1 116.8 3.8 387.4 63.5 103.9 2.1SH7-75 2165 15514 1.8 0.1077 8.0 0.0163 3.6 0.45 103.9 3.7 103.9 7.9 102.4 169.5 103.9 3.7SH7-32 476 6621 2.0 0.1145 3.9 0.0166 2.6 0.67 105.9 2.8 110.1 4.1 201.0 67.8 105.9 2.8SH7-36 1893 6880 13.9 0.1247 5.4 0.0170 3.8 0.70 108.9 4.1 119.3 6.0 331.3 86.8 108.9 4.1SH7-33 531 4233 2.0 0.1303 4.9 0.0173 2.1 0.43 110.4 2.3 124.3 5.7 400.2 98.9 110.4 2.3SH7-29 876 9541 2.5 0.1258 8.3 0.0176 7.5 0.90 112.7 8.4 120.3 9.4 273.2 81.0 112.7 8.4SH7-09 679 10779 2.4 0.1301 4.8 0.0178 2.8 0.59 113.5 3.2 124.2 5.6 335.5 88.2 113.5 3.2SH7-07 646 9365 3.0 0.1320 5.9 0.0180 4.1 0.70 114.8 4.7 125.9 7.0 341.0 95.7 114.8 4.7SH7-55 644 9147 2.0 0.1321 7.0 0.0181 5.6 0.80 115.6 6.5 126.0 8.3 325.4 96.1 115.6 6.5SH7-53 297 9813 2.6 0.1545 5.0 0.0224 3.8 0.74 142.8 5.3 145.9 6.9 195.5 78.4 142.8 5.3SH7-70 359 5321 1.9 0.1573 5.7 0.0226 2.9 0.50 143.9 4.1 148.3 7.8 220.2 113.3 143.9 4.1SH7-21 136 2319 1.3 0.1410 8.8 0.0226 5.0 0.57 144.2 7.2 134.0 11.0 -44.5 175.5 144.2 7.2SH7-52 194 3296 1.5 0.1642 6.8 0.0227 4.2 0.62 144.5 5.9 154.4 9.7 308.8 121.2 144.5 5.9SH7-47 373 5118 1.2 0.1626 5.4 0.0229 3.9 0.73 146.1 5.7 153.0 7.6 260.4 84.5 146.1 5.7SH7-20 169 2619 1.5 0.1443 6.6 0.0230 4.2 0.64 146.3 6.1 136.9 8.5 -24.1 123.2 146.3 6.1SH7-03 283 1773 1.2 0.1953 15.4 0.0232 4.6 0.30 147.9 6.7 181.1 25.6 640.0 318.0 147.9 6.7SH7-06 155 3690 2.0 0.1591 11.9 0.0242 6.1 0.51 154.2 9.3 149.9 16.6 83.5 243.6 154.2 9.3SH7-27 957 51990 2.1 0.7297 3.8 0.0931 3.3 0.87 573.6 17.9 556.4 16.1 486.4 41.3 573.6 17.9SH7-59 390 46140 2.6 1.8579 1.5 0.1812 1.1 0.73 1073.3 10.6 1066.3 9.7 1051.8 20.2 1073.3 10.6SH7-46 79 9249 1.7 1.9875 2.6 0.1889 1.9 0.75 1115.3 19.9 1111.3 17.4 1103.4 34.0 1115.3 19.9SH7-31 79 12851 0.9 2.2060 4.5 0.2051 2.9 0.64 1202.7 31.3 1183.0 31.4 1147.0 68.9 1202.7 31.3SH7-17 150 12859 2.1 2.0074 3.5 0.1862 3.0 0.84 1100.7 30.0 1118.0 24.0 1151.8 38.7 1100.7 30.0SH7-02 39 4158 1.1 1.7567 5.9 0.1629 4.2 0.71 972.7 37.9 1029.6 38.5 1152.6 83.5 1152.6 83.5SH7-34 61 8783 1.2 1.8419 3.1 0.1701 2.5 0.79 1012.4 23.1 1060.5 20.4 1161.0 37.4 1161.0 37.4SH7-44 32 4326 1.7 2.7559 3.3 0.2236 2.4 0.71 1300.7 27.8 1343.7 24.9 1412.8 45.3 1412.8 45.3SH7-63 213 42206 1.5 3.8528 2.6 0.2798 2.0 0.76 1590.4 27.9 1603.9 20.9 1621.5 31.1 1621.5 31.1SH7-41 337 46855 2.0 4.4336 2.1 0.2961 1.6 0.78 1671.9 23.8 1718.6 17.1 1776.0 23.4 1776.0 23.4SH7-05 434 70190 2.4 4.5648 3.2 0.3011 1.6 0.51 1696.9 24.3 1742.9 26.7 1798.5 50.2 1798.5 50.2SH7-26 243 25167 2.1 4.8134 10.1 0.3172 8.6 0.85 1776.3 133.7 1787.2 85.2 1800.1 96.3 1800.1 96.3SH7-56 294 66402 1.4 10.8244 1.8 0.4697 1.3 0.76 2482.1 27.5 2508.2 16.4 2529.3 19.3 2529.3 19.3
SH8 (Santa Susana Formation; Simi Hills)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
SH8-75 1524 12073 2.1 0.0771 3.3 0.0111 1.5 0.44 71.0 1.0 75.4 2.4 215.4 68.7 71.0 1.0SH8-70 1056 5300 2.7 0.0852 4.2 0.0117 2.4 0.57 74.8 1.8 83.0 3.3 324.7 78.3 74.8 1.8SH8-55 927 8298 1.4 0.0807 3.5 0.0118 2.3 0.66 75.3 1.7 78.8 2.7 186.6 62.3 75.3 1.7SH8-64 1027 9143 1.6 0.0812 4.5 0.0118 3.1 0.68 75.9 2.3 79.2 3.4 182.8 77.2 75.9 2.3SH8-33 1108 7785 1.9 0.0868 3.2 0.0123 1.0 0.31 78.6 0.8 84.5 2.6 253.5 69.4 78.6 0.8SH8-69 374 3213 1.5 0.0914 5.3 0.0124 1.9 0.36 79.6 1.5 88.8 4.5 345.9 111.6 79.6 1.5SH8-49 361 17110 1.1 0.0948 7.8 0.0124 6.9 0.89 79.8 5.5 91.9 6.8 420.9 79.9 79.8 5.5SH8-14 632 6789 1.4 0.0875 4.9 0.0126 3.1 0.62 80.7 2.5 85.1 4.0 211.3 89.8 80.7 2.5SH8-39 1277 8575 1.3 0.0856 3.6 0.0126 2.1 0.60 80.9 1.7 83.4 2.9 153.4 67.2 80.9 1.7SH8-29 837 6102 1.3 0.0856 5.9 0.0127 5.1 0.87 81.4 4.1 83.4 4.7 141.1 67.5 81.4 4.1SH8-25 525 5575 1.7 0.0906 8.9 0.0129 7.1 0.79 82.8 5.8 88.1 7.5 234.8 124.8 82.8 5.8SH8-41 1172 3706 1.1 0.0968 7.7 0.0130 6.5 0.84 83.3 5.4 93.8 6.9 369.5 92.7 83.3 5.4SH8-06 708 5898 1.4 0.0959 4.6 0.0131 2.4 0.53 84.0 2.0 93.0 4.1 329.7 87.8 84.0 2.0SH8-56 966 5437 1.0 0.0949 3.9 0.0131 2.4 0.62 84.0 2.0 92.0 3.5 304.5 70.8 84.0 2.0SH8-52 929 7194 1.6 0.0915 6.6 0.0133 5.4 0.82 85.2 4.5 88.9 5.6 187.4 88.7 85.2 4.5SH8-40 801 5115 1.0 0.0910 3.3 0.0133 2.2 0.68 85.4 1.9 88.4 2.8 169.3 56.1 85.4 1.9SH8-61 750 3598 2.0 0.0990 5.2 0.0134 3.3 0.63 85.8 2.8 95.9 4.8 354.1 91.4 85.8 2.8SH8-31 399 2847 2.3 0.0911 10.2 0.0134 3.4 0.33 85.9 2.9 88.5 8.6 161.0 224.9 85.9 2.9SH8-19 1009 6683 0.6 0.0937 4.1 0.0134 2.4 0.59 85.9 2.1 91.0 3.6 225.2 76.0 85.9 2.1SH8-03 2008 10912 1.5 0.0909 7.0 0.0135 6.5 0.93 86.8 5.6 88.3 5.9 131.3 60.8 86.8 5.6SH8-58 510 2370 1.5 0.1070 6.1 0.0138 3.0 0.49 88.1 2.6 103.2 6.0 468.3 117.9 88.1 2.6SH8-23 753 7023 2.3 0.1068 6.5 0.0138 2.6 0.40 88.4 2.3 103.0 6.3 455.7 131.5 88.4 2.3SH8-15 460 5928 1.7 0.0987 7.9 0.0138 6.7 0.85 88.6 5.9 95.6 7.2 271.9 95.8 88.6 5.9SH8-05 1109 4061 2.0 0.1007 3.5 0.0141 1.9 0.54 90.1 1.7 97.4 3.3 279.7 67.6 90.1 1.7SH8-07 328 1636 1.6 0.0956 6.9 0.0141 2.9 0.41 90.2 2.6 92.7 6.1 158.0 147.4 90.2 2.6SH8-20 688 9229 1.4 0.1029 7.0 0.0142 5.0 0.72 90.6 4.5 99.4 6.6 315.3 110.9 90.6 4.5SH8-47 316 2123 0.9 0.1014 5.3 0.0142 2.4 0.46 90.9 2.2 98.1 4.9 276.0 107.3 90.9 2.2SH8-36 1737 11677 12.2 0.0924 2.8 0.0143 1.9 0.68 91.4 1.7 89.8 2.4 47.7 49.4 91.4 1.7SH8-38 454 3446 1.1 0.0993 8.2 0.0144 4.4 0.53 92.2 4.0 96.1 7.5 195.5 161.3 92.2 4.0SH8-72 548 6924 1.9 0.0958 5.7 0.0146 3.6 0.63 93.2 3.3 92.9 5.1 86.2 105.4 93.2 3.3SH8-60 108 2661 1.6 0.1084 16.0 0.0147 9.4 0.59 94.2 8.8 104.5 15.9 347.5 294.1 94.2 8.8SH8-17 1095 9010 1.8 0.1016 4.0 0.0148 2.7 0.69 94.4 2.5 98.3 3.7 193.6 67.1 94.4 2.5SH8-27 930 4942 1.0 0.1006 8.3 0.0148 3.0 0.37 94.7 2.8 97.3 7.7 160.2 180.5 94.7 2.8SH8-50 132 1791 2.2 0.1092 15.2 0.0148 4.5 0.29 95.0 4.2 105.3 15.2 344.4 331.0 95.0 4.2SH8-53 656 3408 1.1 0.1102 8.1 0.0149 1.7 0.21 95.3 1.6 106.1 8.2 355.3 179.6 95.3 1.6
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
SH8-48 330 3356 1.1 0.1096 7.6 0.0149 2.6 0.34 95.7 2.4 105.6 7.6 336.2 161.1 95.7 2.4SH8-42 387 2860 1.9 0.1121 6.2 0.0150 1.5 0.24 96.0 1.4 107.9 6.4 379.6 135.6 96.0 1.4SH8-10 1989 11101 3.4 0.0971 2.1 0.0150 1.3 0.63 96.0 1.2 94.1 1.9 46.7 38.6 96.0 1.2SH8-26 575 5142 3.7 0.1031 5.4 0.0150 3.3 0.61 96.0 3.2 99.7 5.2 187.8 100.3 96.0 3.2SH8-71 793 7458 1.7 0.1047 4.7 0.0150 3.1 0.65 96.1 2.9 101.1 4.5 220.8 82.9 96.1 2.9SH8-57 429 4123 1.5 0.1013 3.8 0.0152 1.9 0.49 96.9 1.8 98.0 3.6 123.1 78.9 96.9 1.8SH8-65 1186 11729 2.2 0.0994 2.7 0.0152 1.4 0.54 97.4 1.4 96.2 2.5 67.6 53.6 97.4 1.4SH8-37 462 2547 1.4 0.1052 5.7 0.0154 2.3 0.40 98.3 2.2 101.6 5.5 178.9 122.7 98.3 2.2SH8-16 504 2587 1.6 0.1085 5.7 0.0155 3.1 0.53 99.3 3.0 104.6 5.7 227.8 112.4 99.3 3.0SH8-66 576 3670 2.1 0.1136 5.0 0.0156 2.1 0.42 99.6 2.1 109.3 5.2 326.7 102.7 99.6 2.1SH8-04 1473 12529 5.6 0.1000 2.8 0.0156 1.5 0.53 99.7 1.5 96.8 2.6 27.0 57.8 99.7 1.5SH8-18 836 8870 2.5 0.1116 3.4 0.0158 2.5 0.74 100.7 2.5 107.4 3.4 258.5 51.4 100.7 2.5SH8-74 283 3645 1.8 0.1053 6.4 0.0159 2.8 0.44 101.4 2.8 101.6 6.2 107.4 135.9 101.4 2.8SH8-54 609 1754 1.7 0.1201 10.0 0.0159 3.2 0.32 101.5 3.2 115.1 10.9 406.6 213.6 101.5 3.2SH8-32 654 5524 0.9 0.1148 4.8 0.0162 3.6 0.74 103.5 3.7 110.3 5.1 261.1 74.6 103.5 3.7SH8-28 532 4036 2.6 0.1152 4.9 0.0163 2.0 0.41 104.1 2.1 110.7 5.2 256.8 102.9 104.1 2.1SH8-13 561 4715 1.4 0.1258 16.1 0.0164 3.2 0.20 104.6 3.3 120.3 18.3 442.9 353.2 104.6 3.3SH8-09 474 4150 1.5 0.1141 4.0 0.0165 2.2 0.56 105.7 2.3 109.7 4.1 198.4 76.8 105.7 2.3SH8-22 199 5103 1.5 0.1191 13.2 0.0166 7.7 0.58 105.9 8.1 114.3 14.3 292.5 245.7 105.9 8.1SH8-45 1218 10240 1.0 0.1083 3.2 0.0166 1.5 0.46 106.4 1.5 104.5 3.2 60.7 67.9 106.4 1.5SH8-46 131 1599 1.1 0.1018 19.3 0.0167 4.6 0.24 106.8 4.9 98.4 18.2 -99.3 465.1 106.8 4.9SH8-73 237 2803 1.3 0.1112 7.9 0.0169 4.0 0.51 108.2 4.3 107.1 8.0 83.0 162.1 108.2 4.3SH8-44 353 4158 1.9 0.1201 6.1 0.0169 2.9 0.47 108.3 3.1 115.2 6.6 259.2 123.6 108.3 3.1SH8-63 352 4580 1.8 0.1250 6.1 0.0170 3.2 0.52 108.7 3.4 119.6 6.9 342.3 118.3 108.7 3.4SH8-21 122 1047 1.3 0.0950 10.5 0.0172 4.4 0.42 109.7 4.8 92.1 9.2 -340.9 244.8 109.7 4.8SH8-01 567 4204 1.6 0.1146 4.4 0.0172 2.3 0.52 110.1 2.5 110.2 4.6 112.9 88.7 110.1 2.5SH8-35 194 1985 1.2 0.1131 13.2 0.0175 2.9 0.22 112.1 3.2 108.8 13.6 36.8 308.6 112.1 3.2SH8-51 299 2857 0.7 0.1317 12.9 0.0193 9.1 0.71 123.0 11.1 125.7 15.3 176.3 212.7 123.0 11.1SH8-08 320 3017 1.4 0.1460 3.8 0.0213 2.2 0.57 135.9 2.9 138.4 4.9 180.6 72.7 135.9 2.9SH8-11 394 3232 0.5 0.1886 8.6 0.0253 6.5 0.75 161.3 10.3 175.4 13.9 370.4 127.9 161.3 10.3SH8-30 212 2608 1.9 0.1798 6.0 0.0260 2.8 0.46 165.3 4.5 167.9 9.2 204.9 122.8 165.3 4.5SH8-34 380 4544 2.0 0.1859 4.7 0.0260 1.2 0.24 165.6 1.9 173.1 7.6 276.6 105.5 165.6 1.9SH8-62 686 14407 2.4 0.2036 5.4 0.0291 5.0 0.93 184.6 9.2 188.2 9.4 232.7 47.4 184.6 9.2SH8-59 391 24563 1.2 0.3230 7.1 0.0408 5.6 0.78 258.0 14.1 284.2 17.7 505.4 98.1 258.0 14.1SH8-67 95 20931 2.8 2.7877 2.9 0.2235 2.5 0.87 1300.3 29.8 1352.2 21.7 1435.4 27.4 1435.4 27.4SH8-43 244 32432 2.7 3.9791 3.1 0.2629 2.2 0.70 1504.5 29.6 1629.9 25.5 1795.8 40.8 1795.8 40.8SH8-68A 377 99542 1.2 7.5984 4.0 0.3923 2.9 0.72 2133.3 52.3 2184.7 36.1 2233.2 48.6 2233.2 48.6
SM8 (Tuna Canyon Formation; Santa Monica Mountains)Isotope ratios Apparent ages (Ma)
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
SM8-47 594 3932 1.2 0.0886 5.4 0.0130 2.2 0.41 83.4 1.8 86.2 4.5 163.5 115.9 83.4 1.8SM8-70 385 6475 2.8 0.0981 5.7 0.0135 2.6 0.45 86.6 2.2 95.1 5.1 312.6 114.9 86.6 2.2SM8-32 300 2924 1.4 0.0931 7.4 0.0136 2.8 0.37 86.8 2.4 90.4 6.4 186.0 160.8 86.8 2.4SM8-17 968 9448 7.9 0.0948 4.4 0.0136 2.8 0.65 87.1 2.5 91.9 3.8 220.0 76.6 87.1 2.5SM8-66 1033 8165 3.1 0.0951 4.2 0.0136 2.7 0.65 87.2 2.4 92.3 3.7 224.9 73.8 87.2 2.4SM8-02 626 9012 3.3 0.0963 5.9 0.0136 1.8 0.31 87.3 1.6 93.3 5.3 249.3 129.5 87.3 1.6SM8-69 337 4474 2.8 0.0907 4.5 0.0137 2.4 0.53 87.6 2.1 88.2 3.8 103.3 89.9 87.6 2.1SM8-07 359 3806 2.3 0.0972 4.8 0.0138 2.1 0.44 88.2 1.9 94.2 4.3 249.7 99.5 88.2 1.9SM8-38 614 4967 3.7 0.0946 4.2 0.0138 1.7 0.41 88.5 1.5 91.8 3.7 177.4 88.9 88.5 1.5SM8-57 371 3933 2.2 0.0976 7.3 0.0139 2.4 0.33 88.7 2.1 94.5 6.6 244.7 158.8 88.7 2.1SM8-51 1060 11781 2.2 0.0979 4.5 0.0139 3.4 0.75 88.7 3.0 94.8 4.0 252.7 67.4 88.7 3.0SM8-21 512 8343 1.5 0.0981 4.7 0.0139 2.4 0.51 89.2 2.1 95.0 4.3 243.1 93.7 89.2 2.1SM8-60 428 3279 1.9 0.0966 10.2 0.0139 7.1 0.69 89.2 6.3 93.6 9.1 206.3 169.7 89.2 6.3SM8-36 432 4516 2.6 0.0990 5.3 0.0140 2.4 0.46 89.4 2.2 95.8 4.8 258.1 107.3 89.4 2.2SM8-12 822 3524 1.2 0.1045 6.3 0.0140 1.6 0.25 89.7 1.4 100.9 6.1 374.0 137.9 89.7 1.4SM8-26 1114 12284 6.0 0.0984 2.1 0.0140 1.5 0.70 89.8 1.3 95.3 2.0 234.8 35.2 89.8 1.3SM8-54 477 5797 4.8 0.0972 5.9 0.0141 2.2 0.37 89.9 1.9 94.2 5.3 202.7 126.7 89.9 1.9SM8-08 665 6518 2.6 0.0979 4.2 0.0141 2.2 0.53 90.0 2.0 94.8 3.8 216.9 81.5 90.0 2.0SM8-53 418 3395 5.1 0.0952 5.3 0.0141 2.4 0.45 90.1 2.1 92.3 4.7 149.8 110.7 90.1 2.1SM8-23 1549 15056 2.7 0.0951 2.3 0.0141 1.6 0.68 90.1 1.4 92.2 2.0 147.3 39.6 90.1 1.4SM8-34 275 2436 1.1 0.0935 7.6 0.0141 3.1 0.40 90.2 2.7 90.8 6.6 105.2 164.4 90.2 2.7SM8-35 470 4195 2.1 0.0954 7.5 0.0142 3.6 0.48 90.6 3.2 92.5 6.6 142.9 154.7 90.6 3.2SM8-46 122 1530 1.8 0.0895 17.3 0.0142 4.6 0.27 90.8 4.1 87.1 14.4 -14.5 404.7 90.8 4.1SM8-67 809 7602 4.0 0.1065 3.2 0.0142 1.9 0.58 91.2 1.7 102.7 3.1 379.7 58.6 91.2 1.7SM8-58 316 3416 3.3 0.1022 9.7 0.0143 2.7 0.28 91.4 2.4 98.8 9.1 281.7 213.6 91.4 2.4SM8-64 144 1953 5.0 0.0886 11.9 0.0143 5.2 0.44 91.6 4.8 86.2 9.9 -60.0 262.1 91.6 4.8SM8-63 251 2581 1.7 0.0865 10.8 0.0143 2.2 0.20 91.8 2.0 84.2 8.7 -126.5 262.2 91.8 2.0SM8-04 302 3585 3.0 0.0972 9.9 0.0144 2.5 0.25 92.0 2.3 94.2 8.9 150.1 224.4 92.0 2.3SM8-39 699 9340 2.2 0.1045 4.0 0.0145 3.1 0.76 93.1 2.9 100.9 3.9 289.2 59.7 93.1 2.9SM8-40 301 2495 2.5 0.1104 11.2 0.0147 2.7 0.24 94.0 2.5 106.4 11.3 394.0 244.8 94.0 2.5SM8-24 273 2443 1.1 0.0968 6.3 0.0148 3.7 0.58 94.5 3.4 93.8 5.6 75.5 121.0 94.5 3.4SM8-31 327 3341 1.6 0.1061 6.8 0.0150 1.9 0.29 95.9 1.8 102.4 6.6 257.4 148.8 95.9 1.8SM8-41 158 1975 1.6 0.0952 10.8 0.0150 4.1 0.38 96.2 4.0 92.4 9.5 -4.9 241.3 96.2 4.0SM8-19 956 10745 2.3 0.1069 3.0 0.0151 1.3 0.45 96.9 1.3 103.1 2.9 249.1 60.8 96.9 1.3SM8-11 297 2855 0.9 0.1018 6.1 0.0152 3.1 0.51 97.4 3.0 98.4 5.8 123.8 124.5 97.4 3.0
Analysis U 206Pb U/Th 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ±(ppm) 204Pb 235U (%) 238U (%) corr. 238U (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma)
SM8-14 758 7341 2.5 0.1094 4.0 0.0154 2.3 0.57 98.7 2.3 105.4 4.0 260.5 75.8 98.7 2.3SM8-20 504 2351 2.3 0.1219 15.3 0.0154 1.7 0.11 98.8 1.6 116.7 16.9 501.1 337.0 98.8 1.6SM8-09 344 3889 2.2 0.1075 4.8 0.0155 1.6 0.33 99.4 1.6 103.6 4.8 202.9 106.1 99.4 1.6SM8-59 587 5142 1.1 0.1088 3.0 0.0157 1.3 0.43 100.2 1.3 104.9 3.0 212.3 62.5 100.2 1.3SM8-49 224 1553 1.5 0.0942 8.5 0.0158 3.5 0.41 101.2 3.5 91.4 7.5 -158.2 193.7 101.2 3.5SM8-03 484 8869 1.5 0.1156 3.8 0.0159 1.9 0.49 101.7 1.9 111.1 4.0 318.0 75.9 101.7 1.9SM8-37 1413 19569 6.3 0.1064 2.6 0.0159 2.0 0.75 101.9 2.0 102.7 2.5 120.3 40.1 101.9 2.0SM8-22 1456 20698 2.7 0.1073 2.6 0.0160 1.4 0.55 102.6 1.5 103.5 2.5 125.5 50.5 102.6 1.5SM8-50 476 3415 1.9 0.1166 5.4 0.0161 4.6 0.85 102.7 4.7 112.0 5.7 314.4 64.4 102.7 4.7SM8-43 863 9166 2.0 0.1137 2.4 0.0161 1.7 0.71 103.1 1.8 109.3 2.5 247.6 39.4 103.1 1.8SM8-10 670 6658 1.7 0.1157 3.5 0.0162 2.6 0.73 103.4 2.6 111.2 3.7 280.2 55.0 103.4 2.6SM8-25 1113 7941 3.0 0.1172 4.0 0.0164 2.0 0.49 104.8 2.0 112.6 4.3 279.3 80.3 104.8 2.0SM8-48 990 12704 7.4 0.1169 2.4 0.0164 1.4 0.56 104.9 1.4 112.2 2.6 271.7 45.9 104.9 1.4SM8-52 927 7307 1.3 0.1144 3.7 0.0164 1.8 0.50 105.0 1.9 110.0 3.8 219.4 73.0 105.0 1.9SM8-61 732 5517 2.1 0.1142 4.3 0.0164 1.9 0.45 105.2 2.0 109.8 4.4 211.4 88.2 105.2 2.0SM8-45 1086 7579 0.8 0.1172 2.8 0.0165 1.9 0.66 105.5 2.0 112.6 3.0 264.8 49.1 105.5 2.0SM8-68 326 3687 2.3 0.1173 4.8 0.0167 2.3 0.49 106.8 2.5 112.6 5.1 237.5 96.0 106.8 2.5SM8-30 359 9363 1.8 0.1226 4.7 0.0170 2.2 0.46 108.7 2.3 117.4 5.2 297.5 94.6 108.7 2.3SM8-28 327 4487 2.5 0.1324 6.6 0.0174 2.6 0.39 111.2 2.9 126.3 7.8 419.9 135.3 111.2 2.9SM8-18 898 11561 8.9 0.5578 3.1 0.0691 2.5 0.80 431.0 10.3 450.1 11.2 548.6 40.5 431.0 10.3SM8-15 446 90018 3.2 2.0089 2.5 0.1881 1.9 0.75 1111.2 19.2 1118.5 17.0 1132.6 33.1 1132.6 33.1SM8-62 139 10710 1.5 1.8872 4.9 0.1706 4.1 0.83 1015.6 38.3 1076.6 32.6 1202.2 54.1 1202.2 54.1SM8-01 202 32270 1.3 2.4645 3.3 0.2152 2.4 0.73 1256.4 27.1 1261.7 23.6 1270.7 43.7 1270.7 43.7SM8-05 77 12571 1.5 2.5813 2.7 0.2201 2.1 0.76 1282.5 24.1 1295.3 20.0 1316.7 34.7 1316.7 34.7SM8-29 211 34217 5.1 2.7729 2.7 0.2284 1.4 0.52 1326.1 16.9 1348.3 20.3 1383.5 44.8 1383.5 44.8SM8-16 193 26663 1.5 2.7446 2.5 0.2255 2.2 0.86 1310.8 25.7 1340.6 18.7 1388.6 24.5 1388.6 24.5SM8-27 206 20015 1.4 2.9853 2.1 0.2383 1.2 0.56 1377.9 14.3 1403.9 15.8 1443.5 32.9 1443.5 32.9SM8-44 69 16586 1.6 3.1756 2.2 0.2524 2.0 0.88 1450.6 25.5 1451.2 17.2 1452.2 19.8 1452.2 19.8SM8-42 241 46476 1.6 3.9756 3.1 0.2802 2.9 0.92 1592.3 40.7 1629.2 25.5 1677.2 23.1 1677.2 23.1SM8-55 599 60686 2.4 4.0218 2.6 0.2833 1.6 0.63 1608.2 23.3 1638.6 21.0 1677.9 37.0 1677.9 37.0SM8-13 461 99961 1.0 13.3049 4.1 0.5091 3.3 0.81 2652.7 72.4 2701.5 38.8 2738.3 39.5 2738.3 39.5SM8-56 122 58267 1.0 14.7764 2.8 0.5233 2.0 0.72 2713.1 44.8 2800.9 26.9 2864.8 32.0 2864.8 32.0
TABLE DR5. AVERAGE DETRITAL MODES OF SELECTED SANDSTONES
Sample group Qt (%)
F (%)
L (%)
M (%)
Lv/Lt P/F
Early-mid Eocene (n = 14) Value 36.3 51.5 12.2 3.3 0.24 0.59 Standard deviation 6.9 7.2 5.8 2.8 0.10 0.10 Standard error 1.8 1.9 1.6 0.8 0.03 0.03 Mid Maastrichtian-Paleocene (n = 23) Value 41.1 47.2 11.7 6.5 0.28 0.56 Standard deviation 9.7 9.7 6.6 5.8 0.23 0.18 Standard error 2.0 2.0 1.4 1.2 0.05 0.04 Campanian-early Maastrichtian (n = 19) Value 35.5 46.2 18.3 7.3 0.23 0.67 Standard deviation 6.2 8.5 10.8 4.7 0.17 0.10 Standard error 1.4 2.0 2.5 1.1 0.04 0.02 Cenomanian-Turonian (n = 3) Value 24.6 35.0 40.4 1.9 0.50 0.90 Standard deviation 2.7 10.6 13.2 1.7 0.11 0.07 Standard error 1.6 6.1 7.6 1.0 0.06 0.04
Note: n—number of samples; Qt—monocrystalline and polycrystalline quartz relative to total QtFL; F—feldspar relative to total QtFL; L—lithic fragments relative to total QtFL; M—framework mica relative to total framework grains; Lv/Lt—fraction of volcanic lithic fragments relative to total lithic fragments; P/F—fraction of plagioclase relative to total feldspar; 300 to 400 grains were counted per sample (mainly the latter); see the Data Repository item for more complete results including standard deviations and standard errors.
Qt(%)
F(%)
L(%)
Qm(%)
K(%)
P(%)
Lm(%)
Lv(%)
Ls(%)
M(%)
Lv/L P/F
Northwest Eoc (n = 2)Avg 44.1 47.3 8.6 47.7 25.0 27.3 63.0 26.4 10.6 1.7 0.26 0.52Stdev 2.3 2.7 5.0 0.3 5.2 5.5 8.8 4.7 4.1 2.4 0.05 0.10Stderr 1.7 1.9 3.6 0.2 3.7 3.9 6.2 3.3 2.9 1.7 0.03 0.07
Northwest KP (n = 11)Avg 40.4 50.6 9.0 43.5 19.1 37.4 62.6 24.9 12.5 7.0 0.25 0.63Stdev 10.9 8.9 5.8 10.7 9.7 18.5 25.3 25.2 11.9 7.3 0.25 0.21Stderr 3.3 2.7 1.7 3.2 2.9 5.6 7.6 7.6 3.6 2.2 0.08 0.06
Northwest Kuu (n = 3)Avg 40.1 47.0 13.0 46.1 20.6 33.3 65.3 29.0 5.8 9.2 0.29 0.61Stdev 5.3 12.4 10.7 8.1 4.6 9.1 36.7 36.3 7.2 6.0 0.36 0.11Stderr 3.1 7.1 6.2 4.7 2.7 5.2 21.2 20.9 4.1 3.4 0.21 0.06
North-central Eoc (n = 5)Avg 34.3 47.0 18.7 41.1 28.3 30.6 55.4 27.6 17.0 2.9 0.28 0.52Stdev 4.8 2.1 3.8 3.8 4.2 6.2 6.1 8.2 8.3 1.3 0.08 0.08Stderr 2.1 0.9 1.7 1.7 1.9 2.8 2.7 3.7 3.7 0.6 0.04 0.04
North-central KP (n = 10)Avg 42.7 44.9 12.4 48.2 26.9 24.9 61.8 28.3 10.0 6.1 0.28 0.47Stdev 8.9 9.7 5.3 9.9 5.5 10.8 21.6 21.9 10.2 4.8 0.22 0.12Stderr 2.8 3.1 1.7 3.1 1.7 3.4 6.8 6.9 3.2 1.5 0.07 0.04
North-central Kuu (n = 13)Avg 33.8 43.9 22.4 42.1 16.9 41.0 51.7 24.7 23.6 7.4 0.25 0.70Stdev 6.3 7.1 9.8 5.7 4.6 8.4 12.8 12.8 9.6 5.0 0.13 0.10Stderr 1.7 2.0 2.7 1.6 1.3 2.3 3.5 3.5 2.7 1.4 0.04 0.03
North-central Klu (n = 3)Avg 24.6 35.0 40.4 38.9 5.7 55.4 37.7 50.0 12.3 1.9 0.50 0.90Stdev 2.7 10.6 13.2 3.4 4.3 7.6 9.9 10.5 3.7 1.7 0.11 0.07Stderr 1.6 6.1 7.6 1.9 2.5 4.4 5.7 6.1 2.1 1.0 0.06 0.04
South-central Eoc (n = 7)Avg 35.5 55.8 8.7 38.2 21.3 40.5 79.2 20.3 0.5 4.0 0.20 0.66Stdev 7.9 8.0 2.4 8.4 4.6 5.9 11.7 11.9 1.3 3.7 0.12 0.05Stderr 3.0 3.0 0.9 3.2 1.7 2.2 4.4 4.5 0.5 1.4 0.04 0.02
South-central KP (n = 2)Avg 37.0 39.9 23.1 47.2 18.0 34.8 45.7 47.7 6.6 5.9 0.48 0.63Stdev 9.7 12.7 3.1 15.2 5.5 20.7 17.4 22.3 4.8 2.5 0.22 0.21Stderr 6.8 9.0 2.2 10.8 3.9 14.6 12.3 15.7 3.4 1.7 0.16 0.15
South-central Kuu (n = 3)Avg 38.1 55.6 6.2 39.7 23.1 37.2 81.6 9.3 9.1 5.2 0.09 0.61Stdev 5.2 5.4 0.5 6.0 1.6 7.0 5.9 5.3 0.8 1.4 0.05 0.05Stderr 3.0 3.1 0.3 3.5 0.9 4.1 3.4 3.1 0.5 0.8 0.03 0.03
Table DR6. AVERAGE DETRITAL MODES OF FOREARC SANDSTONES
Note: See Figure DR2 for definition of the geographic subdivisions. Avg—average; Stdev—standard deviation; Stderr—standard error; n—number of samples; Eoc—early to middle Eocene, Klu—Cenomanian-Turonian; KP—middle Maastrichtian-Paleocene; Kuu—Campanian-early Maastrichtian; F—total feldspar; K—potassium feldspar; L—lithic fragments; Lm—metamorphic lithic fragments; Ls—sedimentary lithic fragments; Lv—volcanic lithic fragments; %M—percent framework mica relative to total framework grains; P—plagioclase feldspar; Qm—monocrystalline quartz; Qt—monocrystalline and polycrystalline quartz; 300 to 400 grains were counted per sample (mainly the latter).
Misc QtFL QmKP LmLvLs