12. PALEOENVIRONMENT AND BIOSTRATIGRAPHY OF …€¦ · sporadic occurrences of planktonic foraminifers prevented zonation of Quaternary and Pliocene intervals, although some interesting

Pisciotto, K. A., Ingle, J. C , Jr., von Breymann, M. T., Barron, J., et al., 1992Proceedings of the Ocean Drilling Program, Scientific Results, Vol. 127/128, Pt. 1

12. PALEOENVIRONMENT AND BIOSTRATIGRAPHY OF FORAMINIFERS AT SITES 794, 795, 796,AND 797 IN THE JAPAN SEA1

Charlotte A. Brunner2

Biostratigraphy and paleoenvironmental history of deep and surficial waters of the Japan Sea are addressed using sequences recoveredfrom the floor of the backarc basin. The study is divided into two parts: (1) foraminifer biostratigraphy and paleoenvironmental assessmentof sedimentary sequences recovered from above igneous basement at the four sites and (2) detailed planktonic foraminifer paleoenvironmentalanalysis of Quaternary and Pliocene sequences from Sites 794 and 797 in the Yamato Basin.

A total of 253 samples were examined for the foraminifer biostratigraphy and 325 samples for the detailed paleoenvironmentalstudy of Quaternary and Pliocene sequences. Low abundance and sporadic occurrence of foraminifers limited interpretation ofresults. Foraminifer-bearing intervals were correlated where possible to diatom and calcareous nannofossil zonations, and thesequences were successfully assigned to the foraminifer zonation of Matsunaga. Unfortunately, extensive barren intervals andsporadic occurrences of planktonic foraminifers prevented zonation of Quaternary and Pliocene intervals, although someinteresting conclusions about paleoenvironment were possible and are listed below.

A sequence of Neogene (sensu lato) paleoenvironmental events were identified: (1) deepening of the Yamato basins to middlebathyal depths by the early to middle Miocene, an event contemporaneous with the age of some deep basins known from upliftedsections adjacent to the Japan Basin; (2) cooling of the Japan Sea in the early middle Miocene; (3) oxygenation of deep watersin the late Miocene; (4) further cooling of surficial water masses between the Olduvai Subchron and the Brunhes/MatuyamaBoundary; and (5) extermination of lower middle bathyal faunas and replacement by upper middle bathyal faunas near the baseof the Quaternary.

INTRODUCTION

A fundamental objective long sought in the Japan Sea region is acontinuous biostratigraphic and paleoenvironmental record of themarginal sea. The scientific reward from such a sequence includesissues of multidisciplinary interest. The paleoenvironmental recordof the backarc basin could detail the events surrounding the openingand subsidence of the nascent basin, its maturation, and the effects ofcompression that may lead ultimately to its destruction. Rotation ofthe island arc during Miocene basin widening along with formationof sills across passages to the open Pacific Ocean probably arerecorded by assemblage changes in the biota of both the upper watercolumn and in bottom waters. The late Pliocene and Quaternary facies(light and dark lithologic cycles) suggest that the basin may have actedlike an amplifier in response to glacial climatic cycles. The developmentof a continuous biostratigraphy correlated to the global time scalecould place these events in historical perspective relative to those inthe Pacific Ocean and elsewhere.

The taxonomy of Japan foraminifers, the foraminifer biostratigraphy,and paleoenvironments of uplifted marine sections on western Honshuand Hokkaido have been discussed by many workers (i.e., Asano,1950-1951; Saito, 1963; Matsunaga, 1963; Asano, et al., 1969;Burckle and Todd, 1976; Kurihara, 1976; Tsuchi et al., 1984; Oda,1986). Several major events in the history of the Japan Sea wereidentified from these sequences.

1. Uplifted bathyal basins are as old as the late early Miocene, adate that marks a youngest age for bathyal depth basins during thebirth process of the backarc basin (i.e., Matoba, 1984).

2. The nascent Japan Sea supported a warm subtropical planktonicfauna in the early Miocene, but was cool by the late middle Miocene(i.e., Asano et al., 1969; Saito, 1963; Matoba, 1984; Tsuchi et al.,1984). This cooling event may be related to clockwise rotation of the

Pisciotto, K. A., Ingle, J. C , Jr., von Breymann, M. T., Barron, J., et al., 1992. Proc.ODP, Sci. Results, 127/128, Pt. 1: College Station, TX (Ocean Drilling Program).

2 Center for Marine Science, University of Southern Mississippi, Stennis SpaceCenter, MS 39529.

island arc, a process that closed southerly passages and openednortherly passages to the Pacific Ocean (Chinzei, 1986).

3. The sedimentary sequence between the early Miocene andPliocene contains sporadic occurrences of foraminifers, making itvery difficult to piece together a history during basin growth andmaturity (i.e., Matsunaga, 1963).

4. Middle Miocene to late Pliocene agglutinated foraminifer fau-nas of the Onnagawa and Funakawa Formations indicate low oxygenconditions in the deep waters of the bathyal basins (i.e., Matoba,1984). The overlying Pleistocene fauna, which is dominated bycalcareous benthic foraminifers, marks a change in deep water tomore oxygenated conditions.

5. Matoba (1984, and references therein) has noted that the late Plioceneto early Pleistocene fauna typified in the Kitaura and Wakimoto Formationsis quite different from the latest Quaternary fauna recovered in piston cores,and he suggests that a drastic change in bathyal Oceanographic conditionstriggered a major faunal turnover in the late Pleistocene.

The objective of this paper is to assess the capability of the dataset to address the goals listed above, to expand on the history knownfrom uplifted sections, and to identify additional significant eventssince the birth of the marginal sea.

METHODS

Neogene Biostratigraphy and PaleoenvironmentalAssessment

Core-catcher samples were prepared from sediment cores of thefour sites, and in a few instances samples were taken from withincores. 253 samples approximately 20 cm3 in volume were dried,soaked in a hot 1% Calgon solution, washed on a sieve of 63-µmopenings, and inspected for foraminifers. In most samples, all specimenswere picked and identified to genus or species. In samples withcommon to abundant foraminifers, representatives of each speciespresent were picked (see Tables 2 and 3 in the Biostratigraphy sectionof each site chapter in Tamaki, Pisciotto, Allan, et al., 1990). Thespecies ranges and assemblages were compared with the zonation ofMatsunaga (1963).

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C. A. BRUNNER

Detailed Quaternary and Pliocene Biostratigraphy andPaleoenvironmental Analysis

Samples were taken from each section of the hydraulically piston-cored portions at Sites 794 and 797. As many as five samples persection were taken in the top five and six cores respectively, and onesample per section from deeper in the sequences. Samples wereweighed, dried, and soaked in a hot 1% Calgon solution for about3 hr. The disaggregated sediment was washed on a sieve of 63-µmopenings, and the sand-size residue was dried, weighed, and inspectedfor foraminifers. Samples with abundant planktonic foraminifers weresplit into about 300 specimens using an Otto microsplitter. Planktonicforaminifers were identified to species and counted, benthic foraminiferswere counted.

Several parameters were calculated from the measured data: sandpercent by weight, planktonic and benthic foraminifer numbers (num-ber of specimens per gram of sediment), benthic/planktonic ratio(number of benthic specimens/total number of foraminifer speci-mens), the coiling ratio of Neogloboquadrina pachyderma (numberof sinistral forms/total number of Neogloboquadrina pachydermatests), and relative frequency of 11 planktonic foraminifer species andcounting groups. Q-mode cluster analysis was used to objectivelyseparate planktonic foraminifer assemblages. The procedure used asimple Euclidean distance coefficient applied to the relative speciesfrequency data and amalgamated samples using the smallest averagedistance between groups. The results were compared to the biostratigra-phy of Maiya et al. (1976) and Lagoe and Thompson (1988).

RESULTS OF NEOGENE FORAMINIFERBIOSTRATIGRAPHY

Foraminifers are generally rare (Table 1) and samples with com-mon to abundant foraminifers are, with a few notable exceptions,limited to the Quaternary and upper Pliocene. Of 65 samples exam-ined at Site 794 (Tables 1 and 2), 27 are barren, 20 have fewer than10 specimens, and only 4 from the Quaternary sequence have morethan 100 specimens, which are dominated by calcareous planktonicforaminifers. Of 68 samples examined at Site 795 (Tables 1 and 3),25 are barren, 7 have fewer than 10 specimens, and 20 have more than100 specimens, which, in general, are dominated by agglutinatedforaminifers. One sample from the middle Miocene sequence bearsmore than 100 calcareous foraminifers. Of 53 samples examined fromSite 796 (Tables 1 and 4), 23 are barren, 11 have fewer than 10specimens, and 6 have greater than 100 specimens. One of the lattersamples is upper Miocene, and the others are Quaternary and upperPliocene. Of 67 samples from Site 797 (Tables 1 and 5), 23 are barren,12 have fewer than 10 specimens, and 13 have more than 100specimens. Three of these lie in the Miocene, whereas the other 10are from the Quaternary and upper Pliocene.

Quaternary Foraminifers

The Quaternary sequences (Koizumi, this volume; L. Vigliotti andJ. Wippern, pers. comm., 1990) at all sites bear several features in

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common (Tables 2 through 5). They contain almost no agglutinatedforaminifers, and have several intervals with abundant subarctic toarctic planktonic foraminifers. The sequences contain some miliolidslike Pyrgo, Nummoloculina, Quinqueloculina, and other genera, andthey have assemblages with frequent Globocassidulina subglobosa,Islandiella norcrossi, Stainforthia complanata, Brizalina pacifica,Epistominella pacifica, Fursenkoina seminuda, Bulimina striata var.mexicana, and Trifarina. There are too few foraminifers in this set ofdata to clearly distinguish benthic assemblages within the Quaternary.

Pliocene Foraminifers

The most distinctive feature of the Pliocene intervals is the con-sistent range of Miliammina echigoensis throughout the four sites(Tables 2 through 5). At all holes except Hole 796B, the top of therange of this taxon lies within the Neodenticula koizumii Diatom Zone(Koizumi, this volume). At all holes except Hole 796B, the bottom ofthe range lies in the Thalassiosira oestrupii Diatom Zone (Koizumi,this volume). The deepest occurrence at Site 794 (Table 2) is a singlespecimen, which lies in the older Neodenticula kamtschatica DiatomZone (Koizumi, this volume). This occurrence could be contamina-tion from upsection as the next occurrence of Miliammina echigoen-sis lies within the Thalassiosira oestrupii Diatom Zone (Koizumi, thisvolume).

Species that occur in the Pliocene (Koizumi, this volume) at allfour sites (Tables 2 through 5) include the agglutinated speciesMartinottiella communis, Eggerella bradyi, and Eggerella sp. A, andthe calcareous species Melonis pompilioides. Species that occur atSites 795, 796, and 797 include Chilostomella oolina and Globobu-limina auriculata. The two sites from the Japan Basin also shareQuinqueloculina akneriana and Oolina globosa. The two sites fromthe Yamato Basin, however, are difficult to compare because Site 794has the worst calcium carbonate preservation and lowest diversity ofthe four sites, whereas Site 797 has the best calcium carbonatepreservation and highest diversity of the four sites.

Upper Miocene Foraminifers

In the Japan Basin, the sequence within the Neodenticula kamt-schatica Diatom Zone (Koizumi, this volume) is nearly barren offoraminifers. In the Yamato Basin, the upper Miocene sediments ofSites 794 and 797 are also near barren except at the base of the zonewhere Sample 127-797-31X-CC, is enriched with well preservedGlobigerina bulloides, Globobulimina auriculata, Sigmavirgulinasp., Cibicides lobatulus, Elphidium subincertum, and traces of otherspecies. This sample may be displaced from shallower depth.

Correlation of foraminifers to the diatom zonation of Koizumi(this volume) is difficult below the uppermost Miocene because ofdiagenesis below the opal-A/opal-CT transition, which lies at vari-ous levels within the upper Miocene at all four sites. Diatom zonesare recognized where diatoms are preserved in carbonate concre-tions. Additionally, calcareous nannofossils provide zonal assign-ments at sporadic intervals (Rahman, this volume). With this caveatin mind, some statements can be made with caution about time andintracore correlations.

The lower part of the upper Miocene sequence in the Japan Basin,approximately equivalent to the Denticulopsis dimorpha DiatomZone (Koizumi, this volume) at Site 795 (Table 3), contains adistinctive assemblage of agglutinated and calcareous foraminifers.The agglutinated foraminifers include Cyclammina cf. C. tani, Cy-clammina pusilla, other Cyclammina species, more than six speciesof Haplophragmoides, more than three species of Ammodiscus,Trochammina spp., Martinottiella communis, Martinottiella nodu-losa, and Eggerella sp. A. The calcareous foraminifers includeMelonis pompilioides, Gyroidina soldanii, and other Gyroidinaspp., Cibicides wuellerstorfi> Globobulimina auriculata, and Glo-bigerina bulloides.

188

JAPAN SEA FORAMINIFERS

Site 796 (Table 4), also from the Japan Basin, bears a similaragglutinated assemblage near its base. The base may be early lateMiocene in age based on extrapolation of sedimentation rates fromdatums higher in the sequence (see Sediment Accumulation Ratessection, Site 796 chapter in Tamaki, Pisciotto, Allan, et al. (1990). Thecalcareous assemblage at Site 796 contains Globobulimina auricu-lata, Gyroidina lamarckiana, Nonionella miocenica, Chilostomellaoolina, Valvulineria spp., and Globigerina woodi among a few others,and looks different from the assemblage at Site 795. However, wecaution that this conclusion is reached based on very few specimens.

The lower part of the upper Miocene sequence in the Yamato Basinis assigned to the Rouxia californica Diatom Zone at Site 797 (Koizumi,this volume). The zone at this site is truncated by a disconformity atits base. The interval (Table 5) includes one specimen of Cyclammina,four species of Haplophragmoides, Martinottiella communis, andEggerella sp. A and is generally similar to the agglutinated assem-blage of the Japan Basin. The calcareous foraminifers include Gyroi-dina lamarckiana, Pullenia salisburyi, Globobulimina auriculata,and other Globobulimina spp., Neogloboquadrina asanoi, and Neoglo-boquadrina himiensis. This list of species is different from those ofthe Japan Basin.

The lower part of the upper Miocene sequence at Site 794 isassigned to the Rouxia californica Diatom Zone through the Denticu-lopsis katayamae Diatom Zone (Koizumi, this volume) above theopal-A/opal-CT transition, which lies in Core 127-794A-3IX. Thebase of the upper Miocene is placed near Sample 127-794A- 14R-CC,based on extrapolation of sedimentation rates and the occurrence ofthe Discoaster hamatus Calcareous Nannofossil Zone in Sample127-794B-12R-CC. Unfortunately, the foraminifers are too rare atSite 794 (Table 2) to compare with those in Site 797 (Table 5).

Middle Miocene Foraminifers

The deepest, foraminifer-bearing unit at Site 795 in the Japan Basinfalls within the Denticulopsis praedimorpha and Denticulopsis hustedtiiDiatom Zones (Koizumi, this volume). The latter zone lies near the baseof the middle Miocene. The sequence (Table 3) bears Cyclammina cf. C.tani and Cyclammina spp. with Eggerella sp. A, several species ofHaplophragmoides, Martinottiella communis, Martinottiella nodulosa,and Spirosigmoilinella compressa. With the exception of the last species,the assemblage of agglutinated foraminifers is similar to the lower upperMiocene agglutinated assemblage at Sites 795 and 796. The calcareousforaminifers at Site 795 include Globobulimina auriculata, Cibicideswuellerstorfi, Elphidium subincertum, Gyroidina lamarckiana, Gyroi-dina orbicularis, Pullenia bulloides, and pieces of nodosarids and singlespecimens of Melonis pompilioides Nonionella spp. and other species.The most common planktonic species are Globigerina bulloides andGlobigerinita glutinata, species commonly associated with cool surficialwater masses.

Middle to Lower (?) Miocene Foraminifers

In the Yamato Basin, the age of foraminifer-bearing sediment nearbasement at Sites 794 and 797 appears coincident. The intervals atSites 794 (Cores 127-794B-24R and-25R) and 797 (Cores 127-797B-47X through -52X) contain the calcareous nannofossil, Sphenolithusheteromorphus (Rahman, this volume), which ranges in age from 14.4to 17.1 Ma (Berggren et al., 1985). Its range crosses the lowerMiocene/middle Miocene boundary. The ranges of several planktonicforaminifers support this conclusion. At Site 797, Samples 127-797B-52X-CC, and -797C-3R-CC, contain Catapsydrax parvulus, whichranges in age from Zone N7 to within Zone N15 (Kennett andSrinivasan, 1983), about 17.6 to 10.2 Ma (Berggren et al., 1985), andGloborotalia praescitula, which ranges in age from Zone N10 (Ken-nett and Srinivasan, 1983), about 14-15 Ma (Berggren et al., 1985),to 17.7 Ma (Berggren et al., 1985). Additionally, Samples 127-797B-51X-CC, -797B-52X-CC, and -794B-24R-CC, are dominated by the

species Globoquadrina venezuelana of the warm subtropics, whichsuggests that the region was much warmer than assemblages higherin the sequences. The paleoenvironmental cooling occurred in theearly middle Miocene (Saito, 1963; Chinzei, 1986).

Sites 794 and 797 have similar assemblages of foraminifers. Site794 (Table 2) contains the agglutinated species Cyclammina cancel-lata, Cyclammina japonica, Cyclammina pusilla, Ammodiscus spp.,more than four species of Haplophragmoides, Martinottiella communis,Martinottiella nodulosa, Spirosigmoilinella compressa, and Trocham-mina spp. The same agglutinated assemblage occurs at Site 797 (Table5) with the additional species, Eggerella sp. A, four additional speciesof Haplophragmoides, and four additional species of Ammodiscus.Site 794 (Table 2) contains the calcareous species Chilostomellaoolina, Gyroidina orbicularis, Gyroidina sp. A, Nonionella mio-cenica, and Oridorsalis tener. Site 797 (Table 5) contains the samecalcareous species with Globobulimina auriculata and other Glo-bobulimina species, Cibicides wuellerstorfi, Eilohedra rotunda, ad-ditional Chilostomella species, Pullenia bulloides, Valvulineriasadonica, and other species.

Most of the calcareous benthic species that occur at Sites 794 and797 (Tables 2 and 5) of the Yamato Basin also occur at Site 795 (Table3) of the Japan Basin. However, the Yamato Basin assemblage is muchmore diverse, and the agglutinated assemblages differ in their cyclam-minid species. The planktonic specimens at Site 795 are few inabundance and poorly preserved in this interval so comparisons withthose at Sites 794 and 797 are unclear. Further work is suggested totest if this interval of Site 795 is correlative with the middle to lower(?)Miocene intervals of the Yamato Basin.

It is interesting to note that the deepest foraminifer-bearing inter-val at Sites 794 and 797 (Tables 2 and 5) is overlain by a distinct barreninterval as are the middle Miocene foraminifer-bearing interval at 795(Table 3) and the upper Miocene foraminifer-bearing intervals at all foursites (Tables 2 through 5).

Paleodepth Analysis

Eighteen calcareous species of benthic foraminifers were selectedas paleodepth indicators based on the work of Matoba (1977), Keller(1980), and Thompson (1980), in the Japan region and that of Ingleand Keller (1980), Culver and Buzas (1986), and Ingle et al. (1980)along the eastern rim of the Pacific Ocean. Occurrences of depthindicators were tabulated (Table 6) by basin and geologic series. Ourinspection of Table 6 reveals the assumptions made about paleodepthindicators, and inspection of Tables 1 through 5 reveals the smallsample size used to draw these conclusions. Sequences bearing ben-thic foraminifers have lain at lower middle bathyal depths since thelower to middle Miocene in the Yamato Basin in units that lie within0.55 m (Site 794) and 0.65 m (Site 797) of igneous basement. Thebasal middle Miocene sequence at Site 795 was also deposited atlower middle bathyal depths in a foraminifer-bearing unit that lies 19m above igneous basement.

Range of the Low Oxygen Facies

At all four sites the lower, middle, and lower upper Miocenesequences bear sedimentary structures suggestive of low oxygen. Thestructures consist of predominance of horizontally oriented burrows inbioturbated sections interspersed with laminated intervals where bio-turbation is absent. The features are described in the barrel sheets ofthe Initial Reports volumes. The ranges of these structures correspondvery well with the ranges of the agglutinated benthic foramini-feralassemblage bearing Cyclammina, Haplophragmoides, and Ammodis-cus, an assemblage associated with low oxygen conditions (Matoba,1984). At all four sites the association appears near the bases of thesedimentary sequences above igneous basement (Table 7). In the JapanBasin the association continues to the Neodenticula kamtschaticaDiatom Zone in the upper upper Miocene of both sites. In the Yamato

189

C. A. BRUNNER

Table 2. Range chart of foraminifers from Site 794 arranged alphabetically within the taxonomic groups, agglutinated, miliolid, rotalid, and planktonic.

Core-sectioninterval (cm)

A-1H-CCA-2H-CCA-3H-02, 94-96A-3H-CCA-4H-05, 90-92A-4H-CCA-5H-CCA-6H-CCA-7H-CCA-8H-CCA-9H-CCA-10H-CCA-11H-CCA-12H-CCA-13H-CCA-14H-CCA-15X-CCA-16X-CCA-17X-CCA-18X-CCA-19X-CCA-20X-CCA-21X-CCA-22X-CCA-23X-CCA-24X-CCA-25X-CCA-26X-CCA-27X-CCA-28X-CCA-29X-CCA-30X-CCA-31X-CCA-32X-CCA-33X-CCA-34X-CCA-35X-CCA-36X-CCA-37X-CCB-1R-CCB-2R-CCB-3R-CCB-4R-CCB-5R-CCB-6R-CCB-7R-CCB-8R-CCB-9R-CCB-10R-CCB-11R-CCB-12R-CCB-13R-CCB-14R-CCB-15R-CCB-16R-CCB-17R-CCB-18R-CCB-19R-CCB-20R-CCB-21R-CCB-22R-CCB-23R-CCB-24R-CCB-25R-CCB-26R-02, 8-9

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A-1H-CCA-2H-CCA-3H-02, 94-96A-3H-CCA-4H-05, 90-92A-4H-CCA-5H-CCA-6H-CCA-7H-CCA-8H-CCA-9H-CCA-10H-CCA-11H-CCA-12H-CCA-13H-CCA-14H-CCA-15X-CCA-16X-CCA-17X-CCA-18X-CCA-19X-CCA-20X-CCA-21X-CCA-22X-CCA-23X-CCA-24X-CCA-25X-CCA-26X-CCA-27X-CCA-28X-CCA-29X-CCA-30X-CCA-31X-CCA-32X-CCA-33X-CCA-34X-CCA-35X-CCA-36X-CCA-37X-CCB-1R-CCB-2R-CCB-3R-CCB-4R-CCB-5R-CCB-6R-CCB-7R-CCB-8R-CCB-9R-CCB-10R-CCB-11R-CCB-12R-CCB-13R-CCB-14R-CCB-15R-CCB-16R-CCB-17R-CCB-18R-CCB-19R-CCB-20R-CCB-21R-CCB-22R-CCB-23R-CCB-24R-CCB-25R-CCB-26R-02, 8-9

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Basin, the shallowest occurrence of the association lies within therange of calcareous nannofossil, Discoaster hamatus, at Site 794 ofthe lower upper Miocene and within the Rouxia californica DiatomZone of the middle upper Miocene at Site 797.

RESULTS OF HIGH-RESOLUTION PLIOCENEAND QUATERNARY BIOSTRATIGRAPHIC

AND PALEOENVIRONMENTAL STUDY

Planktonic foraminifers are limited to a few intervals at Sites 794 and797 in the Yamato Basin. Of 325 samples examined, only 37 sampleshave more than 100 specimens, and 18 have fewer than 100 specimenspicked from the entire sediment sample (Table 8).

There are 37 samples with planktonic foraminifer numbersgreater than 40 tests/g (Fig. 1). Visual inspection of the sand-sizefraction (Table 9) reveals that planktonic foraminifers are the mostabundant constituents of the sand-size fraction in 29 of the 37samples, including two samples that have sand-size gypsum andanhydrite crystals, which may have precipitated from the porewater upon drying in the laboratory and one sample dominated byauthigenic pyrite with foraminifers as the next most commonconstituent. There is a clear relationship between above averagesand content and large foramini-feral number. All samples withgreater than 4,000 planktonic foraminifers/g have above averagesand content, average being 2% for all 325 samples of the data set.There is some relationship between above average sand content andsamples enriched with foraminifers. Sixteen samples are aboveaverage in sand content, and 11 are average or below average.

Eight of the 37 samples (Table 9) are dominated by mineralgrains, authigenic pyrite with mineral grains, ash or pumice, orsponge spicules. Four of these also have an unusually large ratio ofbenthic to planktonic foraminifers, a condition that can indicateshallow source.

The coiling ratio of Neogloboquadrina pachyderma estimatesrelative paleotemperature of surface waters. All samples with 30 ormore specimens of Neogloboquadrina pachyderma were considered(Table 10). At Site 794 (Fig. 2), all 8 samples have 90% or moresinistrally coiled forms. In contrast, Site 797 (Fig. 2) has 34 samples,26 of which have 90% or more sinistrally coiled forms, 7 havebetween 80% and 89%, and one sample, which lies within theOlduvai, has 63% sinistrally coiled forms.

Q-mode cluster analysis was used to distinguish planktonic foraminif-eral assemblages in all samples in which 100 or more specimens werecounted (Table 11). Four clusters were resolved (Fig. 3). Cluster 1 iscomposed of 11 samples, which are dominated (>81%) by sinistralNeogloboquadrina pachyderma. The species has high productionrates when the upper water column is cold, isothermal, and nutrientrich (Sautter and Thunell, 1989; Reynolds and Thunell, 1986). It isalso associated with dissolution because sinistral Neogloboquadrinapachyderma is the most solution resistant of the high-latitude species(Coulbourn et al, 1980; Sautter and Thunell, 1989).

Cluster 2 is composed of 15 samples dominated by sinistralNeogloboquadrina pachyderma with significant amounts of otherspecies, which subdivide the cluster into three groupings, a, b, and c.Cluster 2a includes accessory Globigerina quinqueloba, a speciesassociated with the spring bloom, Cluster 2b includes accessoryGlobigerina bulloides, a species associated with upwelling and a widerange of thermal conditions, and Cluster 2c includes accessory Glo-bigerina bulloides and dextral Neogloboquadrina pachyderma, thelatter of which is associated with the stratified upper water column ofthe temperate fall. The assemblage is consistent with one produced insubarctic waters during seasonal alternation of isothermal and strati-fied conditions. The fauna is, subsequently, only moderately biasedby dissolution (Sautter and Thunell, 1989; 1991).

Cluster 3 is composed of four samples and consists of nearequal proportions of sinistral Neogloboquadrina pachyderma and

193

C. A. BRUNNER

Table 3. Range chart of foraminifers from Site 795 arranged alphabetically within the taxonomic groups, agglutinated, miliolid, rotalid, and planktonic.


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Table 4. Range chart of foraminifers from Site 796 arranged alphabetically within the taxonomic groups, agglutinated, milliolid, rotalid, and planktonic.


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Globigerina bulloides. This association is found in present-daysurficial sediments in the subarctic North Pacific Ocean at waterdepths from 3,300 to 4,300 m (Coulbourn et al., 1980). The assem-blage is produced under the same production conditions as that ofCluster 2, but it is subsequently more strongly dissolved (Sautter andThunell, 1989).

Three samples cluster above the cutoff value and are not suffi-ciently similar to be regarded a cluster. They are most similar tocluster 3. One sample bears a high relative frequency of a speciesrare in all other samples, Tenuitella parkerae. One sample containsnear equal proportions of sinistral Neogloboquadrina pachyderma,Globigerina bulloides, and Globigerina quinqueloba with acces-sory dextral Neogloboquadrina pachyderma. The last sample isdominated by sinistral Neogloboquadrina pachyderma with signifi-cant but small proportions of Globigerina bulloides, Tenuitellaparkerae, and Turborotalita humilis.

Cluster 4 is composed of three samples and is dominated byGlobigerina bulloides. These samples are the most different fromall other samples of the data subset. Globigerina bulloides produc-tion is accelerated during upwelling events (Thunell, pers. coram.,1990) but thrives in a wide range of environments and is not limitedto upwelling habitats especially in temperate and subpolar waters(Sautter and Thunell, 1991).

The Quaternary lithologic sequences at all four sites bear distinc-tive alternations in color between dark chocolate brown, mediumbrown, and light putty gray. It is interesting to note that each plank-tonic cluster has some samples from each color interval (Table 11).

DISCUSSION

Foraminifer Biostratigraphy

The benthic foraminifer sequences described above can be as-signed to the biostratigraphy of Matsunaga (1963) (Table 12), whichwas further described by Matoba (1984) and Matoba et al. (1990) forthe oil fields of Northern Japan. The low abundance of foraminifersat Sites 794 through 797 does not justify comparison to the zonulesdefined by Matsunaga (1963).

Globorotalia cf. G. fohsi Zone

The middle or lower(?) Miocene foraminifer-bearing sequencesat Sites 794 and 797 are tentatively assigned to the Globorotalia cf.G. fohsi Zone. The absence of the subtropical marker species, Glo-borotalia cf. G. fohsi, precludes certain assignment, but the occurrenceof Globorotalia praescitula supports the conclusion. The dominance of asubtropical planktonic foraminifer assemblage suggests that the JapanSea was open to southern waters during deposition of the sequences,a situation expected within the zone. The benthic species listed aresimilar to the bathyal fauna of the Nishikurosawa stage described byMatoba (1984). Some planktonic species listed (Tables 4 and 5) arereported from the Nishikurosawa by Saito and Maiya (1973), al-though some taxonomic questions need resolution.

Spirosigmoilinella compressa Zone

The barren interval above the Globorotalia cf. G. fohsi Zone at Sites794 and 797, the middle Miocene sequence at Site 795, and the upperMiocene sequences at all four sites including the barren interval withinthe Neodenticula kamtschatica Diatom Zone fit the definition of the zone.At all four sites, the lower Pliocene, foraminifer-bearing intervals belowthe first occurrence of Miliammina echigoensis are also assigned to thiszone. Evidence from the planktonic foraminifer fauna support the assign-ment. The cold-water fauna confirms that surficial waters had becomeisolated from subtropical waters that flowed on the Pacific margin of theJapanese islands during deposition of these sequences.

200

Site 794


Site 797

Depth o(mbsf)

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40

60

80

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10 100 1000 10000 1000 10000

Planktonic Foraminiferal Number (tests/g)

Figure 1. Planktonic foraminifer number (number of tests/g of sediment) plotted with depth in core in Hole 794A and Hole 797B. All samples plottedon the y axis are barren of planktonic foraminifers. The two lines connecting the graphs denote the Brunhes/Matuyama Boundary and the top of the

Miliammina echigoensis Zone

The Pliocene sequence that includes the range of Miliamminaechigoensis is assigned to the Miliammina echigoensis Zone. Theinterval extends from the Thalassiosira oestrupii Zone at its base tothe uppermost Neodenticula koizumii Diatom Zone.

The Quaternary interval is not similar to the zonation describedby Matsunaga. The species list, however, is similar to those reportedby Ingle (1975), Matoba (1984), Ujiié et al. (1983), and Kato (1989).

Event: Deepening of the Nascent Backarc Basin

The Yamato Basin has lain at lower middle bathyal depths sincethe middle or early(?) Miocene, and the Japan Basin has been at asimilar depth at least since the middle Miocene (Table 6). Others(Guber and Merrill, 1983; Matoba, 1984) have similarly concludedthat some sections in the Hokuroku District and other regions sur-rounding Akita were bathyal and lower bathyal in depth as early asthe early to middle Miocene. Neritic, upper bathyal, and middlebathyal elements are mixed with lower bathyal species in all of theMiocene sequences. Further, there is no clear change in paleodepthin either the Yamato or Japan basins from the middle or lower(?)Miocene sequences through the Pliocene section. Apparently, sub-sidence of the basin occurred very rapidly after emplacement of theigneous "basement" or during emplacement of the igneous "base-ment." No foraminifers at Sites 794, 795, or 797 are preserved thatrecord the subsidence in sediments above the igneous basement or insediment intercalated amid the igneous basement units.

Event: Early Middle Miocene Cooling

The accuracy of the date of change from subtropical to coldsurficial water in the Japan Sea is not increased by this data set and isessentially no different from that cited by Matoba et al. (1990). Itoccurs above the base of the Sphenolithus heteromorphus Zone andwithin or below the base of the Denticulopsis praedimorpha DiatomZone of the middle middle Miocene based on paleoenvironmentalinterpretation of the planktonic foraminifers at Sites 794, 795, and797 (Tables 2, 3, and 5). Samples in the Sphenolithus heteromorphusZone at Site 794 and 797 contain subtropical species. Two samples,127-795B-27R-CC, and 127-795B-13R-CC, contain no subtropicalspecies and are dominated by Globigerina bulloides and Globigerinacf. G. bulloides, which are characteristic of transitional faunas. Anassemblage that includes high-latitude Neogloboquadrina pachydermaappears at Site 794 within or below the Denticulopsis katayamae DiatomZone of the late Miocene. Like land-based sections, the ODP sequencesare plagued with barren intervals and unconformities.

Event: Oxygenation of Stagnant Miocene Deep Water

Matoba (1984) and others relate the range of agglutinated assem-blages in the Miocene to low-oxygen conditions. The ranges ofCyclammina-Ammodiscus-Haplophragmoides assemblages in the Mio-cene correspond with the occurrence of distinctive intervals domi-nated by horizontal burrows (Table 7) described by the shipboardsedimentologists (Tamaki, Pisciotto, Allan, et al., 1990). The upper-most occurrence of the association lies in the upper upper Miocene

201

Table 5. Range chart of foraminifers from Site 797 arranged alphabetically within the taxonomic groups, agglutinated, milliolid, rotalid, and planktonic.

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C. A. BRUNNER



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A-1H-CCB-1H-CCB-2H-CCB-3H-CCB-4H-CCB-5H-CCB-6H-CCB-7H-CCB-8H-CCB-9H-CCB-10H-CCB-1IH-CCB-12H-CCB-13H-CCB-14H-CCB-15H-CCB-16H-CCB-17H-CCB-18H-CCB-19H-CCB-20X-CCB-21X-CCB-22X-CCB-23X-CCB-24X-CCB-25X-CCB-26X-CCB-27X-CCB-28X-CCB-29X-CCB-30X-CCB-31X-CCB-32X-CCB-33X-CCB-34X-CCB-35X-CCB-36X-CCB-37X-CCB-38X-CCB-39X-CCB-40X-CCB-41X-CCB-42X-CCB-43X-CCB-44X-CCB-45X-CCB-46X-CCB-47X-CCB-48X-CCB-49X-CCB-50X-CCB-51X-CCB-52X-CCC-1R-CCC-2R-CCC-3R-CCC-6R-CCC-7R-CCC-8R-02, 36-38C-18R-01,88-90C-20R-02, 42^4C-22R-CCC-23R-CCC-25R-06, 33-35C-27R-CCC-33R-O3, 42^4C-34R-CC

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A-1H-CCB-1H-CCB-2H-CCB-3H-CCB-4H-CCB-5H-CCB-6H-CCB-7H-CCB-8H-CCB-9H-CCB-10H-CCB-11H-CCB-12H-CCB-13H-CCB-14H-CCB-15H-CCB-16H-CCB-17H-CCB-I8H-CCB-19H-CCB-20X-CCB-21X-CCB-22X-CCB-23X-CCB-24X-CCB-25X-CCB-26X-CCB-27X-CCB-28X-CCB-29X-CCB-30X-CCB-3IX-CCB-32X-CCB-33X-CCB-34X-CCB-35X-CCB-36X-CCB-37X-CCB-38X-CCB-39X-CCB-40X-CCB-41X-CCB-42X-CCB-43X-CCB-44X-CCB-45X-CCB-46X-CCB-47X-CCB-48X-CCB-49X-CCB-50X-CCB-51X-CCB-52X-CCC-1R-CCC-2R-CCC-3R-CCC-6R-CCC-7R-CCC-8R-02, 36-38C-18R-01,88-90C-20R-02, 42^4C-22R-CCC-23R-CCC-25R-06, 33-35C-27R-CCC-33R-03,42-UC-34R-CC

18

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205

C. A. BRUNNER



A-1H-CCB-1H-CCB-2H-CCB-3H-CCB-4H-CCB-5H-CCB-6H-CCB-7H-CCB-8H-CCB-9H-CCB-10H-CCB-11H-CCB-12H-CCB-13H-CCB-14H-CCB-15H-CCB-16H-CCB-17H-CCB-18H-CCB-19H-CCB-20X-CCB-21X-CCB-22X-CCB-23X-CCB-24X-CCB-25X-CCB-26X-CCB-27X-CCB-28X-CCB-29X-CCB-30X-CCB-31X-CCB-32X-CCB-33X-CCB-34X-CCB-35X-CCB-36X-CCB-37X-CCB-38X-CCB-39X-CCB-40X-CCB-41X-CCB-42X-CCB-43X-CCB-44X-CCB-45X-CCB-46X-CCB-47X-CCB-48X-CCB-49X-CCB-50X-CCB-51X-CCB-52X-CCC-1R-CCC-2R-CCC-3R-CCC-6R-CCC-7R-CCC-8R-02, 36-38C-18R-01,88-90C-20R-02, 42^4C-22R-CCC-23R-CCC-25R-06, 33-35C-27R-CCC-33R-03, 42^4C-34R-CC

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B-26X-CCB-27X-CCB-28X-CCB-29X-CCB-30X-CCB-31X-CCB-32X-CCB-33X-CCB-34X-CCB-35X-CCB-36X-CCB-37X-CCB-38X-CCB-39X-CCB-40X-CCB-41X-CCB-42X-CCB-43X-CCB-44X-CCB-45X-CCB-46X-CCB-47X-CCB-48X-CCB-49X-CCB-50X-CCB-51X-CCB-52X-CCC-1R-CCC-2R-CCC-3R-CCC-6R-CCC-7R-CCC-8R-02, 36-38C-18R-01,88-90C-20R-02, 42-44C-22R-CCC-23R-CCC-25R-06, 33-35C-27R-CCC-33R-O3, 42-44C-34R-CC

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207

C. A. BRUNNER

Table 6. Summary of benthic foraminifer upper depth limits and species distribution in the Yamato and Japan Basins.

UpperDepthLimit

NNN

UB<UMB<UMB>UMBUMB

>UMB>UMB<MBMB

LMBLMB

>LMB>LMB>LMB>LMB

Species

Cibicides lobatulusElphidium subincertumNonionella miocenicaEpistominella pacificaChilostomella oolina

Stainforthia complanataGyroidina orbicularis

Bulimina striataCibicides wuellerstorfi

Oridorsalis tenerPullenia salisburyi

Islandiella norcrossiEggerella bradyiGlobobulimina

auriculataMartinottiella communis

Pullenia bulloidesMelonis pompilioides

Gyroidina soldanii

Quaternary

X

X

X

X

Pliocene

XX

X

X

Yamato Basin

upperupper

Miocene

XX

X

lowerupper

Miocene

X

X

mid-lower

Miocene

X

X

X

XX

X

X

Quaternary

X

X

X

X

Japan Basin

Pliocene

XX

X

X

lowerupper

Miocene

X

X

X

X

XX

midMiocene

XX

X

X

X

XX

N neritic depth (<200 m)UB upper bathyal depth (150-500 m)

<UMB upper middle bathyal to shallower depths (<l ,500 m)UMB upper middle bathyal depth (500-1,500 m)

>UMB upper middle bathyal to greater depths (>500 m)< MB middle bathyal to shallower depths (<2,500 m)MB middle bathyal depth (500-2,500 m)

LMB lower middle bathyal depth (1,500-2,500 m)>LMB lower middle bathyal to greater depths (>l ,500 m)

in the Japan Basin and the lower, upper, and middle upper Miocenein the Yamato Basin. Based on this evidence, low-oxygen bottomwaters persisted through much of the Miocene but oxygenated bottomwaters were well established by the uppermost Miocene, and similarconditions persisted throughout the Pliocene sequence. It is interest-ing to consider whether or not high-latitude Late Miocene coolingmight have driven renewal of Japan Sea deep water.

Event: Appearance of Anomalously Shallow QuaternaryFauna

The Quaternary fauna appears shallower than that of the oldersequences (Table 6) because it bears middle to upper bathyal species,but the present lower bathyal depth of the basin argues against sucha shallowing. The anomalous fauna is either entirely displaced fromshallow depth, or unusual conditions in the silled Japan Sea haveexcluded a lower bathyal fauna. The change to this unusual Quater-nary fauna that was originally pointed out by Matoba (1984, andreferences therein) occurs near the Pliocene/Pleistocene Boundaryrather than in the upper Pleistocene. The event may be related toshallowing of sills, which exclude from the marginal sea the deepfauna on the Pacific side of the Japan islands, and to altered bathyalconditions that exterminated the Pliocene fauna.

Detailed Pliocene and Quaternary PlanktonicForaminifer Biostratigraphy

Correlation of the Japan Sea sequences to the assemblage zonesof Maiya et al. (1976) is not possible because abundant occurrencesof planktonic foraminifers are limited mostly to the upper Quaternary.Furthermore, preservation is sporadic with many gaps within theupper Quaternary sequence. The deepest sample that bears planktonicforaminifers at Site 797 contains only Neogloboquadrina pachy-derma with no Neogloboquadrina asanoi and lies within the upper-most Olduvai Subchron. This is consistent with the date of the last

appearance of Neogloboquadrina asanoi at the base of the OlduvaiSubchron as reported by Maiya et al. (1976) and confirmed by Lagoeand Thompson (1988).

Correlation to the coiling direction zones of Lagoe and Thompson(1988) is not possible because all Quaternary samples are dominated(>80%) by sinistral Neogloboquadrina pachyderma (Table 10), andno dextral coiling intervals were found even though both sequencescontain the Brunhes/Matuyama Boundary (at 38.4 mbsf in Hole 797Band at 24.6 or 34.1 mbsf in Hole 794A; L. Vigliotti and J. Wippern,pers. comm., 1990) at which the CD8/CD9 coiling change boundaryis expected from near 90% sinistral forms above to near 50% sinistralforms below. The ratio of 63% sinistral forms in the Olduvai sampleof Site 797 is higher than predicted if it lies with Zone CD11, whichspans the middle and upper Olduvai sequence. The Holocene intervalof dextral coiling is absent either due to disturbance during thedrill-string entry into the bottom or due to dissolution beneath theCCD, which lies between 1,500 and 2,000 m water depth (Ichikuraand Ujiié, 1976) in the Holocene Japan Sea.

Character of the Upper Water Column during theQuaternary

Cluster analysis separates four distinct groupings of planktonicforaminifers in this data set (Fig. 3, Table 11). Cluster 1 is a coldsubarctic fauna produced during isothermal subarctic conditions,Cluster 2 is a well-preserved subarctic fauna produced by seasonalalternation of isothermal and stratified conditions, Cluster 3 is asubarctic fauna that appears similar to the more-dissolved end mem-ber of Cluster 2, and Cluster 4 is an upwelling(?) fauna.

The succession of clusters up-hole can be interpreted environmen-tally (Fig. 4). The deepest sample at Hole 797B is an unclusteredsample with an assemblage most like that of the present-day transi-tional biogeographic province (Coulbourn et al., 1980). Between 50and 40 mbsf, samples alternate between the cold, subpolar Cluster 1and the seasonal, well-preserved subpolar Cluster 2. Near the

208


Table 7. Cores bearing a low oxygen facies determined by style of bioturbation and by foraminiferassemblage.

Yamato Basin

Occurrences of horizontallyflattened burrows and

laminations

Hole 794B

12R13R14R15R16R17R

20R21R22R24R25R26R

Hole 797C

34X

41X43X44X46X47X48X49 X51X52X2R

5R6R

8R

Occurrences of Cyclammina-Haplophragmoides-

Ammodiscus assemblage

Hole 794B

13R14R

18R

24R25R26R

Hole 797C

33X

35X36X37X

47X48X

5IX52X2R3R

6R7R8R

Japan Basin

Occurrences of horizontally Occurrences of Cyclammina-flattened burrows and Haplophragmoides-

laminations

Hole 796B

11R12R14R15R18R

28R29R30R

32R

Hole 795B

1R2R3R7RLOR11RI2RI3RI4R15R16R17R18R19R

21R22R23R24R25R26R27R28R29R30R3IR32R

Ammodiscus assemblage

Hole 796B

19R28R29R

31R32R

Hole 795B

7R10R11R12R13RI4R15R16R17R18R

20R2IR

23R24R

28R29R30R

Brunhes/Matuyama boundary at 38.40 mbsf, samples alternate be-tween the cold subpolar Cluster 1 and the seasonal, somewhatdissolved Cluster 3. Between 35 and 28 mbsf, approximately 0.57Ma, the surface-water column alternates between the seasonalsubarctic conditions represented by Cluster 2 and upwelling(?)conditions represented by Cluster 4. Above 25 mbsf, conditionsreturn to those seen deeper in the core (between 50 and 40 mbsf) andalternate between the cold, subpolar Cluster 1 and the seasonal,well-preserved subpolar Cluster 2. A similar alternation of these twoclusters is observed in the upper Pleistocene sequence of Hole 794A.

The four assemblages defined by the cluster analysis resemblethe assemblages in latest Pleistocene piston cores from the JapanSea, including the Globigerina bulloides enriched assemblage ofCluster 4 (Ujiié and Ichikura, 1973; Ichikura and Ujiié, 1976; Kato,1984). In contrast, the Olduvai sample of Hole 797B has no latestPleistocene or Holocene analog in the Japan Sea, but resembles thefauna of the modern transitional North Pacific Ocean (Coulbourn etal., 1980).

CONCLUSIONS

1. The abundance of foraminifers, in general, is low at all sites inthe deep Japan and Yamato basins. Preservation, diversity, and abun-dance of the calcareous fauna are best at Site 797 and worst at Site794. The assemblages of agglutinated foraminifers are best developedat Sites 795 and 796 in the Japan Basin.

2. The succession of benthic foraminifers in the Neogene se-quences can be assigned to the zonation of Matsunaga (1963), whereasthe planktonic foraminifers of the Quaternary cannot be assigned tothe zonations of Maiyaet al. (1976) or Lagoe and Thompson (1988).

3. Both the Japan and Yamato basins had subsided to lower middlebathyal depths by the time the first foraminifer-bearing sedimentswere deposited above igneous basement at the three sites wherebasement was drilled.

4. The Miocene cooling of the Japan Basin occurred in the earlymiddle Miocene. The data set does not yield improved resolution ofthe event compared to land-based sequences.

2(W

C. A. BRUNNER

Table 8. Listing of data including total sediment weight, weight of sand-size fraction, percent sand-size material by weight, fraction (split) of sampleexamined for foraminifers, planktonic and benthic foraminifer numbers, benthic/planktonic ratio, coiling ratio of Neogloboquadrina pachyderma, thenumber of planktonic and benthic tests counted, and relative frequency taxa of planktonic foraminifers.

Sample 127-

794A-1H-1,2-4 cm794A-1H-1,62-64794A-1H-1,93-98794A-1H-1, 135-137794A-1H-2, 21-24794A-1H-2.65-67794A-1H-2, 93-98794A-1H-2, 133-136794A-1H-3, 26-28794A-1H-3, 65-67794A-1H-3, 69-70794A-1H-3, 93-98794A-1H-4, 26-31794A-1H-4, 56-58794A-1H-4, 92-94794A-1H-4, 136-138794A-1H-5, 3-5794A-1H-5, 25-27794A-2H-1,22-24794A-2H-1,50-53794A-2H-I.96-98794A-2H-1, 118-120794A-2H-1, 142-144794A-2H-2, 10-12794A-2H-2, 50-52794A-2H-2, 113-116794A-2H-2, 136-138794A-2H-3, 8-11794A-2H-3, 56-58794A-2H-3, 96-98794A-2H-3, 127-129794A-2H-3, 135-138794A-2H-4, 17-20794A-2H-4, 46-49794A-2H-4, 87-89794A-2H-4, 96-98794A-2H-4, 132-135794A-2H-5, 10-12794A-2H-5, 39-42794A-2H-5, 77-79794A-2H-5, 96-98794A-2H-5, 126-128794A-2H-6, 8-10794A-2H-6, 17-20794A-2H-6, 84-87794A-2H-6, 91-93794A-2H-6, 96-98794A-2H-6, 99-102794A-2H-7, 8-10794A-2H-7, 48-50794A-3H-1, 23-25794A-3H-1,65-67794A-3H-1,94-99

Depth(mbsf)

0.020.620.931.351.712.152.432.833.263.653.693.934.765.06•5.425.866.036.257.027.307.767.988.228.408.809.439.669.88

10.3610.7611.0711.1511.4711.7612.1712.2612.6212.9013.1913.5713.7614.0614.3814.4715.1415.2115.2615.2915.8816.2816.5316.9517.24

SandWeight

0.11830.01070.04310.19570.21010.08520.33090.13330.32700.01050.02530.11560.02750.01040.00930.01920.00000.65840.02200.01310.12090.06480.19350.25700.20410.09730.09360.05050.01660.00190.10090.10100.16380.08830.00620.00000.00390.00520.01910.03980.13800.12620.12670.37390.06080.21460.83400.02130.01640.00770.02520.12%1.2430

SedWeight

6.89404.5130

13.241020.473010.27605.6200

13.26308.8800

10.87105.26802.3920

11.446023.0630

7.35906.98607.2040

11.510011.199010.97108.19509.8870

10.845011.496012.840012.32109.6230

11.746010.88408.95809.8430

12.49309.3420

12.151011.81707.92287.35709.33408.29007.11409.21408.3130

10.48548.1140

12.069010.67407.1680

10.98306.82608.41506.63747.66809.7010

21.1400

Sand%

1.720.240.330 . %2.041.522.491.503.010.201.061.010.120.140.130.270.005.880.200.161.220.601.682.001.661.010.800.460.190.020.811.081.350.750.080.000.040.060.270.431.661.201.563.100.572.997.590.310.190.120.331.345.88

Split

1.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00000.00391.00001.00000.00101.00001.00001.00001.00001.00000.0012

PlaNum

00

30000000140000000000000000000000000000000

641642

027770

10000

13836

BenNum

0000000000000000000000000000000000000000000

19100

145700000

394

B/PRat

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10000000000

000000000000000000000

3005000003

CoilRat

00

10000

1000000

100100

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00000000000000000000000000000

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092

1000000

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00

4603100

012

480000000000000000000000000000000

302444

0305

50000

351

#Ben

00000

00000040100000000000000000000000000000900

1600000

10

Part.%

00

2400

1000000

5085

0000000000000000000000000000000

9238

05140

0000

67

PacR%

00000000000000000000000000000000000000000002204000001

Bui%

00

740

100000000

1200000000000000000000000000000006

580

1360

0000

14

Umb%

00000000000000000000000000000000000000000000100000000

Qui%

0020000000

5020000000000000000000000000000000010600000

17

Glu%

000000000

1000000000000000000000000000000000000000000000

Min%

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Uvu%

00000000000000000000000000000000000000000000001000000

Par%

0000000000000000000000000000000000000000000000

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Hum%

0000000000000000000000000000000000000000000000

13000000

Ind%

00000000000000000000000000000000000000000000001000000

210



Sample 127-

794A-3H-1, 117-120794A-3H-2, 19-22794A-3H-2, 65-67794A-3H-2, 119-121794A-3H-3, 5-7794A-3H-3, 46-49794A-3H-3, 119-121794A-3H-4, 24-26794A-3H-4, 51-53794A-3H-4, 94-99794A-3H-4, 119-122794A-3H-5, 31-33794A-3H-5, 65-67794A-3H-5, 93-98794A-3H-5, 116-118794A-3H-6, 25-27794A-3H-6, 56-58794A-3H-6, 94-98794A-3H-6, 117-119794A-3H-7, 24-26794A-3H-7, 33-35794A-3H-7, 54-58794A-4H-1,29-32794 A-4H-1,65-67794A-4H-1,93-99794A-4H-1, 117-119794A-4H-2, 47^9794A-4H-2, 74-77794A-4H-2, 99-105794A-4H-2, 144-146794A-4H-3, 29-31794A-4H-3, 64-67794A-4H-3, 94-100794A-4H-3, 142-144794A-4H-4, 38-41794A-4H-4,47-50794A-4H-4, 90-95794A-4H-4, 132-134794A-4H-5, 12-15794A-4H-5, 46-49794A-4H-5, 118-121794A-4H-6, 17-20794A-4H-6, 92-94794A-4H-6, 95-100794A-4H-6, 99-102794A-4H-7, 32-34794A-4H-7, 40-42794A-5H-1, 15-17794A-5H-1, 80-83794A-5H-1,92-97794A-5H-1, 134-136794A-5H-2, 13-16794A-5H-2, 71-73794A-5H-2, 93-97794A-5H-2, 142-145

Depth(mbsf)

17.4717.9918.4518.9919.3519.7620.4921.0421.3121.7421.9922.6122.9523.2323.4624.0524.3624.7424.9725.5425.6325.8426.0926.4526.7326.9727.7728.0428.2928.7429.0829.4429.7430.2230.6830.7731.2031.6231.9232.2632.9833.4734.2234.2534.2935.1235.2035.4536.1036.2236.6436.9337.5137.7338.22

SandWeight

1.02760.10020.19380.02100.00830.03860.20120.32630.71200.07670.09010.08040.07550.08410.12820.00800.01790.57280.18180.01520.06970.03420.00940.20630.52800.20161.04100.16220.41630.03180.01780.05410.01800.02790.13170.18433.47460.04400.11020.03070.00900.00360.16480.00000.15060.12811.52190.23250.09220.47810.02280.03320.19280.42930.0579

SedWeight

10.887010.146011.41906.84919.1821

12.97805.0730

14.764012.522021.860010.276010.486012.838020.546013.02809.69839.0520

23.402012.91808.03809.8020

18.22407.6150

14.306028.384012.75409.56608.6340

22.446010.28308.22109.1447

17.61909.5600

10.634011.459018.98809.5920

10.95809.19409.04809.42369.3352

22.10007.5660

14.918114.58809.5742

11.141020.8400

8.54308.0790

14.747025.2900

9.1830

Sand%

9.440.991.700.310.090.303.972.215.690.350.880.770.590.410.980.080.202.451.410.190.710.190.121.441.861.58

10.881.881.850.310.220.590.100.291.241.61

18.300.461.010.330.100.041.770.001.990.86

10.432.430.832.290.270.411.311.700.63

Split

0.00201.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00000.15631.00001.00000.00201.00001.00001.00001.00001.00001.00001.00001.0000

PlaNum

22366000000000000000020000000000000000000000000

8900

1127600000000

BenNum

1056000000000000000000000000000000000000000000000

17100000000

B/PRat

500000000000

0000000000000000000000000000000000100000000

CoilRat

9800000000

1000000000

900000000000000000000000000

9000

960000000

#Pla

4870000000060000000

410000000000000000000000000

30600

32900000000

#Ben

23000000000000000000000000000000000000000000000500000000

PacL%

7700000000

1000000000

0000000000000000000000000

6500

9100000000

PacR%

1000000000000000020000000000000000000000000700400000000

Bui9c

180000000000000000

760000000000000000000000000

2600000000000

Umb%

00000000000000000000000000000000000000000001

00000000000

Qui%

1000000000000000000000000000000000000000000000400000000

Glu%

0000000000000000000000000000000000000000000000000000000

Min%

0000000000000000000000000000000000000000000000

000000000

Uvu7c

0000000000000000000000000000000000000000000000000000000

Par%

2000000000000000000000000000000000000000000000000000000

Hum%

0000000000000000000000000000000000000000000000000000000

Ind%

0000000000000000000000000000000000000000000000000000000

211

C. A. BRUNNER


Sample 127-

794A-5H-3, 27-30794A-5H-3, 66-68794A-5H-3, 93-97794A-5H-3, 135-137794A-5H-4, 8-10794A-5H-4, 22-25794A-5H-4, 54-57794A-5H-4, 92-97794A-5H-5, 93-98794A-5H-6, 93-98794A-6H-1,92-97794A-6H-2, 92-97794A-6H-3, 90-96794A-6H-4, 92-97794A-6H-5, 93-98794A-6H-6, 84-89794A-7H-1,92-96794A-7H-2, 94-96794A-7H-3, 92-96794A-7H-4, 92-96794A-7H-5, 92-96794A-7H-6, 92-96794A-8H-1,93-97794A-8H-2, 93-97794A-8H-3, 93-97794A-8H-4, 93-97794A-8H-5, 93-97794A-8H-6, 94-98794A-9H-1,93-97794A-9H-2, 93-97794A-9H-3, 93-97794A-9H-4, 93-97794A-9H-5, 93-97794A-9H-6, 93-97794A-1 OH-1,93-97794A-10H-2,93-97794A-10H-3,93-97794A-10H^, 93-97794A-10H-5,93-97794A-10H-6,93-97794A-UH-1,92-96794A-1IH-2,92-96794A-11H-3.91-95794A-1IHA 93-97794A-11H-5,93-97794A-11H-6,93-97794A-12H-1,93-97794A-12H-2,93-97794A-12H-3,93-97794A-12H-4,93-97794A-12H-5,93-97794A-12H-6,93-97794A-13H-1,92-97794A-13H-2,92-97794A-13H-3,93-97

Depth(mbsf)

38.5738.9639.2339.6539.8840.0240.3440.7242.2343.7345.7247.2248.7050.2251.7353.1455.2256.7258.2259.7261.2262.7264.7366.2367.7369.2370.7372.2474.2375.7377.2378.7380.2381.7383.7385.2386.7388.2389.7391.2393.2294.7296.2197.7399.23

100.73102.73104.23105.73107.23108.73110.23112.22113.72115.22

SandWeight

0.32200.26130.31700.17020.00420.19340.13600.00790.03810.02050.03640.13920.61920.03750.07590.00000.01020.00690.03780.05050.01970.00930.01970.21960.12840.03540.01740.16010.13920.10290.10900.19550.69520.86200.24330.19190.65800.98420.02891.19830.17950.45210.09140.24310.13750.45700.06450.11820.81370.84300.29030.16720.60590.20700.1849

SedWeight

8.636010.102025.1400

8.01007.20407.3970

13.730017.596018.465017.936015.932024.281017.985017.626016.934025.420124.757027.308020.87400.0000

20.168322.566016.293019.071019.638015.886014.913018.600014.471016.489016.374013.644013.709010.383011.602614.661017.493011.920017.779019.335017.819017.242015.783016.509017.739013.648015.198015.092016.065021.781014.524016.697016.237017.870015.6080

Sand°h

3.732.591.262.120.062.610.990.040.210.110.230.573.440.210.450.000.040.030.18

0.100.040.121.150.650.220.120.860 .%0.620.671.435.078.302.101.313.768.260.166.201.012.620.581.470.783.350.420.785.073.872.001.003.731.161.18

Split

1.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.0000

PlaNuni

00000000(I00000

00000

00000000000000000000000000000000000

BenNum

0000000000000000000

00000000000000000000000000000000000

B/PRat

00000000000000000000000000000000000000000000

00000000000

CoilRat

000000000000

00000

00000000000000000000000000000000000

000

#Pla

000

000000000000000000000000(I000000000000000000000000000

#Ben

000000000

000

00

00000000000000000000000000000000

000000000

PacLIk

00000000000000000

000000000000000000000000(I0000000000

000

PacR%

00000000000000

00000000000000000000000000000000000000000

Bui%

0000000000000000000000000000000000000000000000000000

000

Umb%

0000000000000000000000000000000000000000000000000000000

Qui%

0000000000000

0000000000000000000000000000000000000

00000

Glu%

000000000000000000000000000000000000000000000000

0000000

Min%

00000000

00000000000000000000000000000000000000000000000

Uvu%

000000000000000

000000000000000000000000000000000000

0000

Par9c

0000000000000000000000000000000000000000000000000000000

Hum%

00

0000000000000000000000000000000000

0000000000000000

000

Ind%

0000000000000

000000000000000000000000000000000000000000

212



Sample 127-

794A-13HA 92-97794A-13H-5, 92-97794A-13H-6, 92-97794A-14H-1, 92-97794A-14H-2, 92-97794A-14H-3,92-97794A-14H4,92-97794A-14H-5,92-97794A-14H-6,92-97797A-1H-1.76-78797A-1H-2, 76-78797A-1H-3, 76-78797A-1H-4, 76-78797A-1H-5, 76-78797B-1H-1,76-78797B-1H-1, 134-136797B-1H-2, 13-15797B-1H-2,44-^6797B-1H-3, 134-136797B-lH^t, 74-76797B-1H-4, 104-106797B-2H-1, 102-104797B-2H-2,76-78797B-2H-3,74-76797B-2H-3, 76-78797B-2H4, 14-16797B-2H-4, 76-78797B-2H-5, 76-78797B-2H-6, 76-78797B-2H-6, 134-136797B-3H-1, 77-79797B-3H-2, 77-79797B-3H-3,77-79797B-3FM, 77-79797B-3H-5,77-79797B-3H-6,77-79797B-3H-6, 103-105797B-3H-6, 135-137797B-3H-7, 14-16797B4H-1,77-79797B4H-2,20-22797B-4H-2,77-79797B^H-3,44-46797B-4H-3,77-79797B-*H-3, 102-104797B-4H-3, 135-137797B4H^, 13-15797B4HA 77-79797B4HA 102-104797B-4H-4, 135-137797B4H-5,43-45797B4H-5,74-76797B-4H-6,77-79797B-4H-6, 135-137797B-5H-1,78-80

Depth(mbsf)

116.72118.22119.72121.72123.22124.72126.22127.72129.22

4.165.667.168.66

10.160.761.341.631.944.345.245.546.928.169.649.66

10.5411.1612.6614.1614.7416.1717.6719.1720.6722.1723.6723.9324.2524.5425.6726.6027.1728.3428.6728.9229.2529.5330.1730.4230.7531.3331.6433.1733.7535.18

SandWeight

0.05860.44590.02240.08560.06740.08060.29950.06110.19910.00000.23840.05310.0109O.i 1920.08350.04120.02090.01010.00960.02400.02800.11460.00000.25440.38850.03580.09170.01060.40810.11010.08910.03870.13500.03500.17020.09990.00930.13710.07990.03270.00270.04390.03530.05710.08380.80970.00930.06610.07210.25880.11240.01930.03000.03190.0927

SedWeight

16.600019.142026.290023.748036.802021.660923.890917.169120.96939.48995.48907.45734.99824.51668.61603.36951.27481.66003.06124.82293.12922.77195.47834.56867.26542.35509.39265.92518.57112.0578

10.36197.22587.18006.10817.12587.54713.82483.55523.74235.46822.88184.98040.76674.95493.25823.23703.16898.19562.30061.77631.64165.75123.39543.39559.5903

Sand%

0.352.330.090.360.180.371.250.360.950.004.340.710.222.640.971.221.640.610.310.500.894.130.005.575.351.520.980.184.765.350.860.541.880.572.391.320.243.862.140.600.090.884.601.152.57

25.010.290.813.13

14.576.850.340.880.940.97

Split

1.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00000.25001.00001.00001.00001.00000.12501.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00000.01560.01561.00001.00001.00001.00001.00000.03130.04691.00001.00000.07810.00780.02341.00001.00000.06251.0000

PlaNum

000000000440000

731174

0II0

35877

0000000

1550200000

125858428

000

5054

33441943

110

1864324078304

0

02837

9

BenNum

0000000000000000

69000

1135

000000000000000

1081593

000

380

125519823

0189144234

00

190

B/PRat

00000000004000

006000

2440000000000000001

16000

430

279

6809030010

CoilRat

000000000

10086

0000

9196

091

09898

0000000

980

2000000

9795

000

80755698

1000

809898

0

09693

#Pla

000000000

38220000

245374

033

0108304

0000000

3190

13

00000

698492

00

038

268341295

350

335449319

20

60283

#Ben

0000000000100001

22000

34120000000000000006

93000

290

1283073

034

290040

PacL%

000000000

7186

0000

6991

064

09771

0000000

8308

00000

7732000

1111

74100

06

7275

00

82

PacR%

0000000000

1400007306021000000020

3100000220003011001120044

Bui%

000000000

2900000

2410

3001

28000000000

5400000

120000

219980

800

872120

10003

45

Umb%

0000000000000000000000000000000000000000000000002100000

Qui''-/<

000000000000000010000000000001080000057000

500

16160033100

110

Glu%

0000000000000000100000000000000000000040000000000000000

Min%

00000000000000000000000000000000000000100000

00o•00000

000

Uvu%

000000000000000020000000000004000000000000

1601100010000

0

Par%

00000000000000001000000000000

1000000003

520000011000100

000

Hum%

0000000000000000000000000000000000000000000000000000000

Ind%

0000000000000000000000000000000000000120000000000020000

213

C. A. BRUNNER


Sample 127-

797B-5H-1, 132-134797B-5H-2,44-46797B-5H-2, 78-80797B-5H-2, 103-105797B-5H-3, 78-80797B-5H^, 43-45797B-5H^, 74-76797B-5H-4, 78-80797B-5H-5, 11-13797B-5H-5,43-45797B-5H-5, 74-76797B-5H-5, 78-80797B-5H-5, 131-133797B-5H-6, 14-16797B-5H-6,78-80797B-5H-6, 102-104797B-5H-7, 14-16797B-5H-7, 43-45797B-6H-1,78-80797B-6H-1, 132-134797B-6H-2, 74-76797B-6H-2, 78-80797B-6H-2, 102-104797B-6H-3, 13-15797B-6H-3, 74-76797B-6H-3, 78-80797B-6H-3, 102-104797B-6H^t, 78-80797B-6H-5, 78-80797B-6H-6, 78-80797B-7H-1, 78-80797B-7H-2, 78-80797B-7H-3, 78-80797B-7H-4, 78-80797B-7H-5, 78-80797B-7H-6, 78-80797B-8H-1, 78-80797B-8H-2, 78-80797B-8H-3, 78-80797B-8HA 77-79797B-8H-5,77-79797B-8H-6, 78-80797B-9H-1, 78-80797B-9H-2, 78-80797B-9H-3, 78-80797B-9H-4,78-80797B-9H-5, 78-80797B-9H-6, 78-80797B-10H-1, 78-80797B-10H-2, 78-80797B-10H-3, 78-80797B-10H-4, 78-80797B-10H-5, 78-80797B-10H-6, 78-80797B-11H-1, 78-80

Depth(mbsf)

35.7236.3436.6836.9338.1839.3339.6439.6840.5140.8341.1441.1841.7142.0442.6842.9243.5443.8344.6845.2246.1446.1846.4247.0347.6447.6847.9249.1850.6852.1854.1855.6857.1858.6860.1861.6863.6865.1866.6868.1769.6771.1873.1874.6876.1877.6879.1880.6882.6884.1885.6887.1888.6890.1892.18

SandWeight

0.06660.09660.29930.O4030.02980.03660.03091.58500.02140.03300.02847.10450.03%0.15870.21030.21360.05530.07250.06140.15040.04270.15050.09180.00870.25870.07460.10020.07250.34090.26060.19970.05240.09140.05030.03280.04820.05660.04050.00370.01500.01720.00990.19710.11700.19120.05440.00910.01990.02760.05190.01310.02840.11550.06970.0981

Sed

Weight

3.90712.42838.84243.02096.25124.24213.8578

10.86502.73292.84483.50869.75982.70383.2753

13.78002.66032.66703.59386.69453.26904.26807.44284.71402.99102.89607.80282.91100.98046.18347.5699

12.95157.07579.88328.8535

11.572710.45098.97619.89365.96827.44285.64976.67638.0221

15.872410.33067.27959.70218.9368

10.040613.41389.11358.5812

15.43008.89988.0499

Sand

1.703.983.381.330.480.860.80

14.590.781.160.81

72.791.464.851.538.032.072.020.924.601.002.021.950.298.930.963.447.395.513.441.540.740.920.570.280.460.630.410.060.200.300.152.460.741.850.750.090.220.270.390.140.330.750.781.22

Split

0.09381.00001.00001.00001.00001.00001.00000.00200.50001.00001.00001.00000.04691.00001.00000.01561.00000.06251.00000.12500.12500.02340.12501.00000.03130.06250.02341.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00000.12501.00001.00001.00001.00001.0000

Pla

Num

881

0

0

113

0

0

61

17073544

51

0

0

26890

0

100480

14290

110

609

2107608

0

3961687

51970

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

361

0

0

0

0

0

Ben

Num

134

0

0

19

0

0

1

46

50

73

0

0

197

0

0

13490

31

0

5

6

17

15

0

177

14

132

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

0

0

0

0

0

B/P

Rat

13

0

0

14

0

0

1

0

8

59

0

0

7

0

0

12

0

2

0

4

1

1

2

0

4

2

2

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

00

0

0

0

0

0

0

0

0

0

0

CoilRat

98

0

0

87

0

0

98

97

98

100

0

0

81

0

0

96

0

87

0

100

90

94

92

0

80

85

91

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

63

0

0

0

0

0

#

Pla

323

0

0

340

0

0

237

371

744

144

0

0

341

0

0

417

0

321

0

45

325

367

358

0

359

335

354

00

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0606

0

0

0

0

0

#

Ben

49

0

0

56

0

0

2

1

68

209

0

0

25

0

0

56

0

7

0

2

3

3

9

0

16

79

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

00

0

0

2

0

0

0

0

n

PacL%

46

0

0

43

0

0

95

56

87

98

0

0

70

0

0

71

0

56

0

73

70

90

82

0

62

84

87

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

00

0

0

0

23

0

0

0

0

0

PacR%

1

0

0

6

0

0

2

2

2

0

0

0

16

0

0

3

0

8

0

0

8

6

8

0

16

14

9

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

13

0

0

0

0

0

Bui

%

49

0

0

48

0

0

3

41

4

1

0

0

9

0

0

4

0

20

0

0

0

1

1

0

15

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

27

0

0

0

0

0

Umb

%

4

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

8

0

13

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

00

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Qui

%

0

0

0

3

0

0

0

1

6

1

0

0

3

0

0

15

0

7

0

0

10

1

3

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

00

0

0

0

0

0

0

0

0

24

0

0

0

0

0

Glu

%

0

0

0

0

0

0

0

0

0

00

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Min

%

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

10

0

0

0

0

Uvu

%

0

0

0

0

0

0

0

0

0

1

0

0

1

0

0

2

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

4

0

0

0

0

0

Par

%

0

0

0

0

0

0

0

0

0

0

0

0

1

0

0

3

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

7

0

0

0

0

0

Hum

%

0

0

0

0

0

0

0

0

0

0

0

0

0

0

00

0

0

00

0

0

0

000

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

000

0

0

0

00

0

Iπd

%

0

0

0

0

0

0

0

0

0

0

0

0

1

0

0

1

0

0

0

13

12

2

7

0

7

1

4

0

0

0

0

0

0

0

0

0

0

0

0

0

0

00

0

0

0

0

0

0

1

0

0

0

0

0

214



Sample 127-

797B-1IH-2, 78-80797B-IIH-3, 78-80797B-1IH-4, 78-80797B-1IH-5. 78-80797B-I1H-6. 78-80797B-12H-1,78-80797B-12H-2, 78-80797B-12H-3, 78-80797B-12H-4, 78-80797B-I2H-5, 78-80797B-12H-6, 78-80797B-13H-1,78-80797B-13H-2, 78-80797B-13H-3, 78-80797B-I3H-4, 78-80797B-13H-5, 78-80797B-13H-6, 78-80797B-I4H-1,78-80797B-14H-2, 78-80797B-14H-3, 78-80797B-14H-4, 78-80797B-14H-5, 78-80797B-15H-1,79-81797B-15H-2, 79-81797B-15H-3, 79-81797B-15H-4, 80-82797B-15H-5, 79-81797B-15H-6, 79-81797B-16H-1,80-82797B-I6H-2, 80-82797B-16H-3, 80-82797B-16H-4, 80-82797B-16H-5, 77-79797B-16H-6, 79-81797B-17H-1,79-81797B-17H-3, 40-42797B-17H-4, 79-81797B-17H-5, 79-81797B-17H-6, 79-81797B-17H-7, 79-81797B-18H-1,80-82797B-I8H-2, 80-82797B-18H-3, 70-72797B-18H-4, 80-82797B-18H-5, 80-82797B-18H-6, 60-62797B-19H-1,79-81797B-19H-2, 79-81797B-19H-3, 79-81797B-19H-4, 79-81797B-19H-5, 79-81797B-19H-6, 79-81

Depth(mbsf)

93.6895.1896.6898.1899.68

101.68103.18104.68106.18107.68109.18111.18112.68114.18115.68117.18118.68120.68122.18123.68125.18126.68130.19131.69133.19134.70136.19137.69139.70141.20142.70144.20145.67147.19149.19150.60151.56153.06154.56156.06158.70160.20161.60163.20164.70166.00167.19168.69170.19171.69173.19174.69

SandWeight

0.09350.06200.05400.09840.17420.25590.00620.03260.06350.09980.08240.00000.09530.25980.28880.15330.18930.14390.16230.09010.07420.22460.10080.03590.02300.03400.05%0.06660.49780.05770.14560.12950.09220.10050.09350.06540.03360.14%0.03450.15300.08630.16110.23100.25060.11720.13600.33180.08020.12040.17430.14520.1300

SedWeight

9.66817.52638.30248.56258.52087.74306.41326.64607.66486.37146.00836.66508.96049.91608.59177.83828.32267.62486.99186.85966.15737.40315.20814.62885.38325.27894.40175.11326.72178.00138.80908.3125

11.78568.10147.43315.81694.35327.35176.19627.64297.36546.69407.46628.66537.37985.57496.53837.61726.94547.13948.04608.3638

Sand%

0.970.820.651.152.043.300.100.490.831.571.370.001.062.623.361.962.271.892.321.311.213.031.940.780.430.641.351.307.410.721.651.560.781.241.261.120.772.030.562.001.172.413.092.891.592.445.071.051.732.441.801.55

Split

1.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.0000

PlaNum

0000000000000000000000000000000000000000000000000000

BenNum

000(I000000000000000000000000000000000000000000000000

B/PRat

0000000000000000000000000000000000000000000000000000

CoilRat

0000000000000000000000000000000000000000000000000000

#Pla

0000000000000000000000000000000000000000000000000000

#Ben

0000000000000000000000000000000000000000000000000000

PacL*

0000000000000000000000000000000000000000000000000000

PacR%

000000000000000000000(I000000000000000000000000000000

Bui%

0000000000000000000000000000000000000000000000000000

Umb%

0000000000000000000000000000000000000000000000000000

Quic/c

0000000000000000000000000000000000000000000000000000

Glu%

0000000000000000000000000000000000000000000000000000

Min%

0000000000000000000000000000000000000000000000000000

Uvu%

0000000000000000000000000000000000000000000000000000

Par%

0000000000000000000000000000000000000000000000000000

Hum%

0000000000000000000000000000000000000000000000000000

Ind%

0000000000000000000000000000000000000000000000000000

Sand weightSed weightSand "ftSplitPla numBen numB/P RatCoil Rat#Pla#BenPACL%PACR %BUL%UMB%QUI%GLU%MIN%UVU%PAR%HUM%IND%

weight of >63-µm fractionweight of the total, dry sediment sample

percent by weight of the >63-µm fractionfraction of the sample counted for foraminifersnumber of planktonic foraminifer tests per gram of sedimentnumber of benthonic foraminiferal tests per gram of sedimentratio: 100 × (planktonic)/(planktonic + benthic foraminifers)ratio: lOO× (sinistral Nq. pachydermala W Nq. pαchxdermα)number of planktonic foraminifers countednumber of benthic foraminifers countedrelative frequency of sinistral Neogloboquadrina pachyderma in planktonic foraminiferal assemblage

ve frequency of dextral Neogloboquadrina pachyderma in planktonic foraminifer assemblageve frequency of Globigerina bulloides in planktonic foraminifer assemblageve frequency of Globigerina umbilicata in planktonic foraminifer assemblageve frequency of Globigerina quinqueloba in planktonic foraminifer assemblageve frequency of Globigerinita glutinata in planktonic foraminifer assemblageve frequency of Globigerinita minuta in planktonic foraminifer assemblageve frequency of Globigerinita uvula in planktonic foraminifer assemblageve frequency of Tenuitella parkerae in planktonic foraminifer assemblage

relative frequency of Turborotalita humilis in planktonic foraminifer assemblagerelative frequency of indeterminate tests in planktonic foraminifer assemblage

215

C. A. BRUNNER

Table 9. Constituents of sand-size fraction.

Sample 127-

794A-2H-6, 17-20 cm794A-2H-6, 84-87794A-2H-6, 96-98794 A-3H-1,94-99794A-3H-1, 117-120794A-4H-6, 95-100794A-4H-7, 40-42797B-1H-1, 134-136797B-1H-2, 13-15797B-2H-1, 102-104797B-2H-6, 134-136797B-3H-6, 135-137797B-3H-7, 14-16797B-4H-3,44-^6797B-4H-3, 77-79797B-4H-3, 102-104797B-4H-3, 135-137797B-4H-4, 102-104*797B-4H-4, 135-137797B-4H-5, 4 3 ^ 5797B-4H-6, 135-137797B-5H-1, 132-134797B-5H-2, 103-105*797B-5H-4, 74-76797B-5H-4, 78-80797B-5H-5, 11-13*797B-5H-5, 4 3 ^ 5797B-5H-5, 131-133797B-5H-6, 102-104*797B-5H-7, 43-45797B-6H-1, 132-134797B-6H-2, 74-76797B-6H-2, 78-80797B-6H-2, 102-104797B-6H-3, 74-76797B-6H-3, 78-80797B-6H-3, 102-104797B-10H-2, 78-80

Depth(mbsf)

14.4715.1415.2617.2417.4734.2535.20

1.341.636.92

14.7424.2524.5428.3428.6728.9229.2530.4230.7531.3333.7535.7236.9339.6439.6840.5140.8341.7142.9243.8345.2246.1446.1846.4247.6447.6847.9284.18

Sand(%)

3.100.577.595.889.44

10.431.221.644.135.353.862.144.601.152.57

25.013.13

14.576.850.941.701.330.80

14.590.781.161.468.032.024.601.002.021.958.930.963.440.39

Plank.foram.number

(#/g)

641642

277701383622366

8911276

731174877155

125858428

5054

334419431864

3240783042837

88111361

17073544

512689

100481429

110609

2107608

3961687

5197361

Major constituent

ForaminifersMinerals

ForaminifersForaminifersForaminifers

GypsumForaminifers

PyriteForaminifersForaminifers

PumiceForaminifersForaminifers

PumiceAnhydrite

ForaminifersPyrite

ForaminifersForaminifersForaminifersForaminifersForaminifers

MineralsMinerals

ForaminifersMinerals

AshForaminifersForaminifersForaminifers

SpiculesForaminifersForaminifersForaminifersForaminifersForaminifersForaminifersForaminifers

Minor constituent-1

MineralsLithic fragments

AnhydriteGypsum

AnhydritePyrite

MineralsMinerals

PyritePyrite

Spicules

Foraminifers

ForaminifersPyrite

Pyrite

PyritePyrite

AnhydriteForaminifers

Radiolarians and Diatoms

SpiculesPyritePyritePyritePyrite

PyriteRadiolarians and Diatoms

PyritePyrite

Minor constituent-2

ForaminifersAnhydrite

RadiolariansRadiolarians

Radiolarians and Diatoms

MineralsForaminifers

SpiculesForaminifers

OrganicsMinerals

MineralsMinerals

MineralsMineralsMinerals

<=thin, foraminifer-rich layer

5. Deep waters of the nascent and mature backarc basin werepoorly oxygenated throughout most of the Miocene sequences. Oxy-genation improved in the uppermost Miocene and continued throughthe Pliocene.

6. The Quaternary assemblage of benthic foraminifers appearsshallower than the basins they were cored from, based on depth rangesof selected foraminifers. The anomalous assemblage was introducedinto the basin near the base of the Pleistocene and persists to thepresent day.

7. Quaternary planktonic assemblages are similar to assemblagesknown from the latest Pleistocene of the Japan Sea, whereas theOlduvai assemblage is similar to present-day faunas of the transitionalNorth Pacific Ocean.

ACKNOWLEDGMENTS

Yasumochi Matoba and Michio Kato deserve special thanks fortheir help and advice concerning identification of benthic foramini-fers and assistance in collection of comparative material from the OgaPeninsula. Ryuji Tada generously provided key samples at Sites 794and 797. Jim Ingle and Tara Kheradyar helped in many useful discus-sions of the data as did Itaru Koizumi, Atiur Rahman, Lisa White,Joanne Alexandrovich, and all my colleagues on board Leg 127. Thereviews by Peter Thompson and Kristin McDougall are greatly ap-preciated as are the editorial comments of John Barron. This researchwas supported by JOI.

REFERENCES

Asano, K., 1950-1951. Illustrated Catalogue of Japanese Tertiary SmallerForaminifera (Parts 1-15): Tokyo (Hosokawa Printing Co.).

Asano, K., Ingle, J. C , Jr., and Takayanagi, Y., 1969. Neogene planktonicforaminiferal sequence in northern Honshu. In Brönniman, R. P., and Renz, H.(Eds.), Proc, lstlnt. Conf. PlanktonicMicrofossils: Leiden (E. J. Brill), 1:14-25.

Berggren, W. A., Kent, D. V., and Van Couvering, J. A., 1985. The Neogene: Part 2.Neogene geochronology and chronostratigraphy. In Snelling, N. J. (Ed.), TheChronology of the Geological Record. Geol. Soc. London Mem., 10:211-260.

Burckle, L. H., and Todd, A., 1976. Correlation of Late Neogene sections ofthe Noto and Oga peninsulas, Japan. In Takayanagi, U., and Saito, T. (Eds.),Progress in Micropaleontology: New York (Micropaleontology Press), 20-26.

Chinzei, K., 1986. Opening of the Japan Sea and marine biogeography duringthe Miocene. J. Geomagn. Geoelectr., 38:487^194.

Coulbourn, W. T., Parker, F. L., and Berger, W. H., 1980. Faunal and solutionpatterns of planktonic foraminifera in surface sediments of the NorthPacific. Mar. Micropaleontol., 5:329-399.

Culver, S. J., and Buzas, M. A., 1986. Distribution of Recent benthic forami-nifera off the North American Pacific coast from California to Baja.Smithsonian Contrib. Mar. Sci., 28:1-634.

Guber, A. L., and Merrill, S., Ill, 1983. Paleobathymetric significance of theforaminifera from the Hokuroku District. Econ. Geol. Monogr., 5:55-70.

Ichikura, M., and Ujiié, H., 1976. Lithology and planktonic foraminifera of theSea of Japan piston cores. Bull. Nat. Sci. Mus., Sen C (Geol.), 2:151-178.

Ingle, J. C , Jr., 1975. Pleistocene and Pliocene foraminifera from the Sea ofJapan, Leg 31, Deep Sea Drilling Project. In Karig, D. E., Ingle, J. C , Jr.,et al., Init. Repts. DSDP, 31: Washington (U.S. Govt. Printing Office),693-701.

216


Ingle, J. C, Jr., and Keller, G., 1980. Benthic foraminiferal biofacies of theeastern Pacific margin between 40°S and 32°N. In Quaternary Deposi-tional Environments of the Pacific Coast. Paleogeogr. Symp. 4, PacificSect., Soc. Econ. Paleontol. Mineral., 341-355.

Ingle, J. C, Jr., Keller, G., and Kolpack, R. L., 1980. Benthic foraminiferalbiofacies, sediments and water masses of the southern Peru-Chile Trencharea, southeastern Pacific Ocean. Micropaleontology, 26:113-150.

Kato, M., 1984. Foraminifera: analysis of the piston core, KH-79-3, C-3.Gekkan Chikyu, 6:529-537.

, 1989. Benthic foraminifers from the Japan Sea piston cores. InTakayanagi, Y., and Ishizaki, K. (Eds.), Collected Papers on Foraminiferafrom the Japanese Islands: Sendai, Japan, 111-116.

Keller, G., 1980. Benthic foraminifers and paleobathymetry ofthe Japan Trench area,Leg 57, Deep Sea Drilling Project. In von Huene, R., Nasu, N., et al., Init. Repts.DSDP, 56,57 (Pt. 2): Washington (U.S. Govt. Printing Office), 835-865.

Kennett, J. P., and Srinivasan, M. S., 1983. Neogene Planktonic Foraminifera:Stroudsburg, PA (Hutchinson Ross).

Kurihara, K., 1976. Correlation of Neogene formations between the Japan Seaand the Pacific coast regions of Japan, by benthonic foraminifera. Rev. Esp.Micropaleontol., 9:307-315.

Lagoe, M. B., and Thompson, P. R., 1988. Chronostratigraphic significance ofLate Cenozoic planktonic foraminifera from the Ventura Basin, California:potential for improving tectonic and depositional interpretation. J. Forami-niferal. Res., 18:250-266.

Maiya, S., Saito, T, and Sato, T, 1976. Late Cenozoic planktonic foraminiferalbiostratigraphy of northwest Pacific sedimentary sequences. In Takay-anagi, Y., and Saito, T. (Eds.), Progress in Micropaleontology: New York(Micropaleontology Press), 395-422.

Matoba, Y, 1977. Recent foraminiferal assemblages off Sendai, northeastern Japan.In Schafer, C. T, and Pelletier, B. R. (Eds.), First Int. Symp, on BenthonicForaminifera of Continental Margins, Maritime Sediments, 205-220.

, 1984. Paleoenvironment ofthe Sea of Japan. In Oertli, J. J. (Ed.), Benthos'83: Proc. 2nd Int. Symp. Benthic Foraminifera (Pau, April 1983), 409-414.

Matoba, Y, Tomizawa, A., Maruyama, T, Shiraishi,T., Aita, Y, and Okamoto,K., 1990. Neogene and Quaternary sedimentary sequences in the Oga Pen-insula. Benthos '90, Proc. 4th Int. Symp. Benthic Foraminifera, Sendai,Japan, Guidebook for Field Trip No. 2: B1-B62 with 12 plates appended.

Matsunaga, T, 1963. Benthonic smaller foraminifera from the oil fields of NorthernJapan. Sci. Rep. Tohoku Univ., Ser. 2, 35:67-122 and 52 plates.

Oda, M., 1986. Some aspects and problems concerned with microfossilbiochronology for the Neogene in Central and Northeast Honshu, Japan.In Nakagawa, H., Kotaka, T, and Takayanagi, Y (Eds.), The Essays onGeology of Professor N. Kitamura: Sendai (Sasaki Print Co.), 195-211.

Reynolds, L., and Thunell, R. C , 1986. Seasonal production and morphologicvariation of Neogloboquadrina pachyderma (Ehrenberg) in the northeastPacific. Micropaleontology, 32:1-18.

Saito, T., 1963. Miocene planktonic foraminifera from Honshu, Japan. 5c/.Rep. Tohoko Univ., Ser. 2, 35:123-209.

Saito, T, and Maiya, S., 1973. Planktonic foraminifera ofthe Nishikurosawa Forma-tion, northeast Honshu, Japan. Trans. Proc. Paleontol. Soc. Jpn., 91:113-125.

Sautter, L. R., and Thunell, R. C, 1989. Seasonal succession of planktonic forami-nifera: results from a four-year time-series sediment trap experiment in thenortheast Pacific. J. Foraminiferal Res., 19:253-267.

, 1991. Planktonic foraminiferal response to upwelling and seasonalhydrographic conditions: sediment trap results from San Pedro Basin,Southern California Bight. J. Foraminiferal Res., 21:347-363.

Tamaki, K., Pisciotto, K., Allan, J., et al., 1990. Proc. ODP, Init. Repts., 127:College Station, TX (Ocean Drilling Program).

Thompson, P. R., 1980. Foraminifers from Deep Sea Drilling Project Sites434, 435, and 436, Japan Trench. In von Huene, R., Nasu, N., et al., Init.Repts. DSDP, 56, 57 (Pt. 2): Washington (U.S. Govt. Printing Office),775-808.

Tsuchi, R., and IGCP-114 National Working Group of Japan, 1984. Neogenechronostratigraphy and bio-events in the Japanese Islands. Paleogeogr.,Paleoclimatol, Paleoecol, 46:38-51.

Ujiié, H., and Ichikura, M., 1973. Holocene to uppermost Pleistocene plank-tonic foraminifers in a piston core from off San'in District, Sea of Japan.Trans. Proc. Palaeontol. Soc. Jpn., 91:137-150.

Date of initial receipt: 18 March 1991Date of acceptance: 5 December 1991Ms 127/128B-124

217

C. A. BRUNNER

Depth 0(mbsf)

80

Site 794

90 100 60 70 80

Site 797

I ' ' I ' ' ' ' ' " ' ' I é ' ' ' ' ',' ' '.

90 100

Coiling Ratio of Sinistral Neogloboquadrina pachyderma (%)

Figure 2. The coiling ratio of Neogloboquadrina pachyderma (sinistral forms/total number of Neogloboquadrina pachyderma in sample) plotted withdepth at Holes 794A and 797B. All samples that plot on the y axis are barren or have fewer than 20 specimens of the species. The two lines connectingthe graphs denote the Brunhes/Matuyama boundary and the top of the Olduvai.

218


Table 10. Coiling ratio of Neogloboquadrina pachy-derma with number of tests of sinistral and dextralforms counted to calculate the ratio.

Sample 127-Depth(mbsf) PacL PacR

794A-1H-3, 93-98 cm794A-2H-6, 17-20794A-2H-6, 84-87794A-2H-6, 96-98794A-3H-1,94-99794A-3H-1,117-120794A-4H-6, 95-100794A-4H-7, 40-42797 A-1H-1,76-78797A-1H-2.76-78797B-1H-1, 134-136797B-1H-2, 13-15797B-1H-3, 134-136797B-1H-4, 104-106797B-2H-1, 102-104797B-2H-6, 134-136797B-3H-6, 135-137797B-3H-7, 14-16797B-4H-3, 135-137797B-4H-4, 13-15797B-4H-4, 102-104797B-4H-4, 135-137797B-4H-5, 43-45797B-4H-6, 135-137797B-5H-1,78-80797B-5H-1, 132-134797B-5H-2, 103-105797B-5H-4, 74-76797B-5H-4,78-80797B-5H-5, 11-13797B-5H-5, 4 3 ^ 5797B-5H-5, 131-133797B-5H-6, 102-104797B-5H-7,43^15797B-6H-1, 132-134797B-6H-2, 74-76797B-6H-2, 78-80797B-6H-2, 102-104797B-6H-3, 74-76797B-6H-3, 78-80797B-6H-3, 102-104797B-10H-2, 78-80

Coil

3.9314.4715.1415.2617.2417.4734.2535.204.165.661.341.634.345.546.9214.7424.2524.5429.2529.5330.4230.7531.3333.7535.1835.7236.9339.6439.6840.5140.8341.7142.9243.8345.2246.1446.1846.4247.6447.6847.9284.18

4127161562323712003012719169339211052162645261402163519

320240487431481462252086481412382681813322633029222128130889

05113262114031713224615740366223321461403392602522275648310

10098949299989096100869196919898989795981008098989693988798979810081968710090949280859163

PacL-number of tests of sinistral Neogloboquadrina pachy-derma counted

PacR-number of tests of dextral Neogloboquadrina pachy der-ma counted

Coil-ratio of sinistral to total number of specimens of Neoglo-boquadrina pachyderma

219

C. A. BRUNNER

EUCLIDEAN DISTANCE COEFFICIENT

EUCLIDEAN DISTANCE COEFFICIENT

Figure 3. Dendrogram of Q-mode analysis of all samples with 100 or morespecimens of planktonic foraminifers.

220


Table 11. Relative frequencies of planktonic foraminifers in samples arranged by cluster.

Sample 127-

Cluster 1794A-2H-6, 17-20 cm794A-4H-7, 40-42797B-1H-2, 13-15797B-1H-4, 104-106797B-2H-6, 134-136797B-5H-4, 74-76797B-5H-5, 11-13797B-5H-5, 4 3 ^ 5797B-6H-2, 78-80797B-6H-2, 102-104797B-6H-3, 78-80797B-6H-3, 102-104

Cluster 2

Subgroup a794A-3H-1,94-99797B-4H-3, 135-137797B-4H-6, 135-137797B-5H-6, 102-104797B-6H-2, 74-76

Subgroup b794A-3H-1,117-120794A-4H-6, 95-100797B-1H-1, 134-136797B-2H-1, 102-104797B-3H-6, 135-137797B-4H-4, 135-137797B-4H-5, 4 3 ^ 5

Subgroup c797B-5H-5, 131-133797B-5H-7, 4 3 ^ 5797B-6H-3, 74-76

Cluster 3794A-2H-6, 84-87797B-5H-1, 132-134797B-5H-2, 103-105797B-5H-4, 78-80

Cluster 4797B-4H-3, 77-79797B-4H-3, 102-104797B-4H-4, 102-104

Unclusterd samples794A-2H-6, 96-98797B-3H-7, 14-16797B-10H-2, 78-80

Depth(mbsf)

14.4735.20

1.635.54

14.7439.6440.5140.8346.1846.4247.6847.92

17.2429.2533.7542.9246.14

17.4734.25

1.346.92

24.2530.7531.33

41.7143.8347.64

15.1435.7236.9339.68

28.6728.9230.42

15.2624.5484.18

Col

11

m1

m1

1/d1m

m/dm

1/m

1dmmm

1dmdmm1

11/dd

11/m1/md

d1

1/d

dmm

PacL

929191978395879890828487

6774827170

77656971777275

705662

38464356

116

513223

PacR

2432222068

149

11438

1771212

168

16

2162

011

42

13

Bui

601103411100

148340

18262428122120

92015

58494841

998087

130

27

Umb

000000000000

00000

0100010

080

1400

002

000

Qui

041010611310

1716111510

1000531

370

1031

0163

67

24

Glu

001000000000

00000

0000000

000

0000

000

040

Min

000000000000

00000

0000000

000

0000

000

011

Uvu

002040010(J00

01020

0000010

100

0000

010

104

Par

0010

100000000

11030

2000310

100

0000

010

1052

7

Hum

000000000000

00000

0000000

000

0000

000

1300

Oth

000000002714

0001

12

0000102

107

0000

000

121

Col sediment colorPacL sinistral Neogloboquadrina pachydermaPacR dextral Neogloboquadrina pachydermaBui Globigerina bulloidesUmb Globigerina umbilicataQui Globigerina quinquelobaGlu Globigerinita glutinataMin Globigerinita minutaUvu Globigerinita uvulaPar Tenuitella parkeraeHum Turborotalita humilisOth other planktonic foraminiferal speciesd dark chocolate brown sedimentm medium brown sediment1 light putty gray sediment

221

C. A. BRUNNER

Table 12. Correlation of diatom and foraminifer zones.

A. Site 794


B. Site 795

Site 794Sample

A-1H-CCA-2H-CCA-3H-2, 94-99A-3H-CCA-4H-5, 90-95A-4H-CCA-5H-CCA-6H-CCA-7H-CCA-8H-CCA-9H-CCA-10H-CCA-11H-CCA-12H-CCA-13H-CCA-14H-CCA-15H-CCA-16X-CCA-17X-CCA-18X-CCA-19X-CCA-20X-CCA-21X-CCA-22X-CCA-23X-CCA-24X-CCA-25X-CCA-26X-CCA-27X-CCA-28X-CCA-29X-CCA-30X-CCA-31X-CCA-32X-CCA-33X-CCA-34X-CCA-35X-CCA-36X-CCA-37X-CCB-7R-CCB-8R-CCB-9R-CCB-10R-CCB-11R-CCB-12R-CCB-13R-CCB-14R-CCB-15R-CCB-16R-CCB-17R-CCB-18R-CCB-19R-CCB-20R-CCB-21R-CCB-22R-CCB-23R-CCB-24R-CCB-25R-CCB-26R-2, 8-9

Diatom andNannofossil

Zones

Neodenticulaseminae

Rhizosoleniacurvirostris

?

Neodenticulakoizumii

,M koizumii,-N. kamtschatica

Thalassiosira

oestrupii

Neodenticulakamtschatica

Rouxiacalifornica

Thalassionemaschraderi

Denticulopsis —katayamae

— Discoasterhamatus

™ SphenolithusA heteromorphis<

ForaminiferZone

7

Miliamminaechigoensis

• Opal-A/Opal-CT ••

Spirosigmoilinellacompressa

Globorotalia cf.G. fohsi

Epoch

Quaternary

Pliocene

lateMiocene

••••••••••••••

middleMiocene

Site 795Sample

A-1H-CCA-2H-CC

A-3H-CCA-4H-CCA-5H-CCA-6H-CCA-7H-CCA-8H-CCA-9H-CCA-10H-CCA-11H-CCA-12H-CCA-13H-CCA-14H-CCA-15H-CCA-16H-CCA-17H-CCA-18H-CCA-19H-CCA-20X-CCA-21X-CCA-22X-CCA-23X-CCA-24X-CCA-25X-CCA-26X-CCA-27X-CCA-28X-CCA-29X-CCA-30X-CCA-31X-CCA-34X-CCA-35X-CCA-36X-CCA-37X-CCA-38X-CCA-39X-CCB-1R-CCB-2R-CCB-3R-CCB-4R-CCB-5R-CCB-6R-CCB-7R-CCB-8R-CCB-9R-CCB-1OR-CCB-11R-CCB-12R-CCB-13R-CCB-14R-CCB-15R-CCB-16R-CCB-17R-CCB-18R-CCB-19R-CCB-20R-CCB-21R-CCB-22R-CCB-23R-CCB-24R-CCB-25R-CCB-26R-CCB-27R-CCB-28R-CCB-29R-CCB-3OR-CCB-31R-CC

Diatom Zone

Neodenticulaseminae

Rhizosolenia

curvirostris

Actinocyclusoculatus


Neodenticulakoizumii-


Thalassiosiraoestrupii

• Opal-A/Opal-CT ••

Neodenticula^ kamtschatica

^ Denticulopsisdimorpha

Denticulopsispraedimorpha

^ Denticulopsispraedimorpha

Denticulopsispraedimorpha

A Denticulopsispraedimorpha

M l

•^ Denticulopsishustedtii

ForaminiferalZone

7



Epoch

Quaternary

Pliocene

lateMiocene

middleMiocene

222


Table 12 (continued). Table 12 (continued).

C. Site 796 D. Site 797

Site 796ASample

A-1H-CCA-2H-CCA-3H-CC

A-4H-CCA-5H-CCA-6H-CCA-8H-CCA-9X-CCA-10X-CCA-11X-CCA-12X-CCA-14X-CCA-15X-CCA-16X-CCA-17X-CCA-18X-CCA-19X-CCA-20X-CCA-21X-CCA-22X-CCA-23X-CCA-24X-CCA-25X-CCA-26X-CCA-27X-CC

Diatom Zone

Neodenticula

seminae

Rhizosolenia

curvirostris—Actinocyclus—

oculπtuiNeodenticula

koizumii

N. koizumii-N. kamtschatica

Thalassiosira

oestrupü


Site 796BSample

B-1R-CC

B-2W-CCB-3R-CCB-4R-CCB-5R-CCB-6R-CCB-7R-CCB-9R-CCB-1OR-CC

B-11R-CCB-12R-CCB-13R-CCB-14R-CCB-15R-CCB-16R-CCB-17R-CCB-18R-CCB-19R-CCB-20R-CCB-24R-CCB-28R-CCB-29R-CCB-3OR-CCB-31R-CCB-32R-3, 31-33B-32R-4, 143-145B-32R-5, 24-26B-33R-2, 34-36

ForaminiferZone



. . Opal-A/Opal-CT «

Diatom Zone

Neodenticulaseminae

R. curvirostris




. JV. kamtschatica _

Epoch

Quaternary

Pliocene

lateMiocene

ForaminiferZone

7


* Opal-A/Opal-CT


Epoch

Quaternary

Pliocene

lateMiocene

Site 797Sample

A-1H-CCB-1H-CCB-2H-CCB-3H-CCB-4H-CCB-5H-CCB-6H-CCB-7H-CCB-8H-CCB-9H-CCB-10H-CCB-l 1H-CCB-12H-CCB-13H-CCB-14H-CCB-15H-CCB-16H-CCB-17H-CCB-18H-CCB-19H-CCB-20X-CCB-21X-CCB-22X-CCB-23X-CCB-24X-CCB-25X-CCB-26X-CCB-27X-CCB-28X-CCB-29X-CCB-30X-CCB-31X-CCB-32X-CCB-33X-CCB-34X-CCB-35X-CCB-36X-CCB-37X-CCB-38X-CCB-39X-CCB-40X-CCB-41X-CCB-42X-CCB-43X-CCB-44X-CCB-45X-CCB-46X-CCB-47X-CCB-48X-CCB-49X-CCB-50X-CCB-51X-CCB-52X-CCC-1R-CCC-2R-CCC-3R-CCC-6R-CCC-7R-CCC-8R-2, 36-38C-18R-1,88-90C-20R-2, 4 2 ^ 4C-22R-CCC-23R-CCC-25R-6, 33-35C-27R-CCC-33R-3,42-44C-34R-CC

Diatom andNannofossil

Zones

Neodenticulaseminae

Rhizosoleniacurvirostris




Thalassiosiraoestrupü


Rouxiacalifornica

Discoasterextensus

Discoasterexilis Zone

Sphenolithusheteromorphis

ForaminiferZone


• •• Opal-A/Opal-CT <


Globorotalia cf.G. fohsi

Epoch

Quaternary

Pliocene

lateMiocene

middleMiocene

early(?)Miocene

223

C. A. BRUNNER

Site 7971

-r

i , . . - , . . . .

i i

_

Upwelling

Unclustered

Subpolar, dissolved

Subpolar, seasonal

Subpolar, cool

Site 794

1 ,

1 ,

1 ,

i, 1

-

20 40

Depth (mbsf)

60 80

Upwelling

Unclustered

Subpolar, dissolved

Subpolar, seasonal

Subpolar, cool

Figure 4. Succession of clusters in Holes 794A and 797B plotted against depth in hole. The subpolar cool assemblage is equivalentto Cluster 1; the subpolar seasonal assemblage is equivalent to Cluster 2; the subpolar, dissolved assemblage is equivalent to Cluster3; the unclustered samples are those distinctly different from all other samples; and the upwelling(?) assemblage is equivalent toCluster 4. The two lines connecting the graphs denote the Brunhes/Matuyama Boundary and the top of the Olduvai.

224

Documents

12. PALEOENVIRONMENT AND BIOSTRATIGRAPHY OF …€¦ · sporadic occurrences of planktonic foraminifers prevented zonation of Quaternary and Pliocene intervals, although some interesting