M. Reese Madrid Geography 81026 May 2003 Prof. Davis

Dune Fields of the Cahuilla Basin:

An Investigation of the Salton, Algodones and

Gran Desierto Dune Fields and Their Relationship

ABSTRACT

There are three separated dune fields in the Cahuilla Basin: Salton, Algodones and GranDesierto. As distinct fields within a limited geographic area, the fields are examined forclues to their connections. Their sand supply appears to be fluvial sediments of theColorado River. Orientation and movement of the dunes within the fields suggests aconsistent wind regime throughout the Basin. Examinations of the structures at eachdune field indicate that competing wind regimes and additional sand sources introduceadditional complexity to the dune fields over the length of the basin. Geographic barriersmay impede the movement of the dune fields and influence physical connections betweenthe fields.

INTRODUCTION

The Lake Cahuilla Basin, also called the Salton Sink or Trough, or Imperial and

Coachella Valleys, by any name, is a single, structural land feature. An alternately filled

and dry lakebed, the basin was filled when the course of the Colorado River shifted to the

north. Once the rivers’ course shifted southward again, the lake evaporated leaving a

supply of beach sand on its shores. The Salton, Algodones and Gran Desierto dune fields

are three distinct dune fields within this Basin (Figure 1).

.Figure 1. Location andorientation of the dune fields inthe Cahuilla Basin, with faultlines. Nb. the unusualorientation of the map. FromLancaster 1995.

The furthest north and west of the dune fields is the Salton Sea field, consisting of

multiple barchan dunes. The Algodones is the middle field and is characterized by mega

barchans. The Gran Desierto is the southernmost field and is characterized by multiple

dune types.

The obvious parallel orientations as seen on a map of the region (Figure 1 above) has lead

many of the researchers examining the Salton, Algodones, and Gran Desierto dune fields

independently to suggest a connection between them. Norris (1966) posits from particle

size and sorting that the isolated Tule Wash dune, west of the Salton Sea, and the Salton

Sea dunes have identical sources. Haff and Presti (1981, 174) projected trajectories of

Salton dunes to the northern tip of the Algodones, stating, “it is possible that at one time a

belt of dunes, and saltating sand, formed a direct connection to the much older Algodones

chain.” Norris and Norris (1961, 610) speculate about the connections between the

Algodones and Gran Desierto dune fields stating “fine-grained wind blown sand and silts

are common in the Gran Desierto…doubtless some sand and silt from the Algodones

Dunes has been blown over the valley of the Colorado in the past to contribute to these

deposits on the Arizona and Sonora side of the river.” Each researcher has wondered

about the dune fields and their potential relationships, however beyond the speculations

presented above, no formal study of their relationship has been made.

Each dune field has progressively more complex dunes structures. Using evidence from

these structures and from limited wind regime data, an analysis of the relationship of the

fields to each other is possible and conclusions can be made about the aeolian processes

at work in the Basin.

GEOGRAPHIC SETTING

The Imperial and Coachella Valleys together form the elongated, Cahuilla Basin (McCoy

et al 1967). It is a 225 km long (Waters 1983), structural basin, 73 meters below sea

level at its lowest elevation and it is the landward extension of the Gulf of California.

The Orocopia, the Chocolate and the Cargo Muchado Mountain ranges bound the region

on the east and the Peninsular ranges create a western barrier (Muhs et al 1995). The

basin is a fluvial, lacustrine and tectonic landscape. Deltaic sediments from the Colorado

River created an elevated barrier at 12m elevation that bisects the region (McCoy et al

1967), as does the river itself. The Basin is a mostly dry lakebed, filled during occasions

of shift in the channel of the Colorado River. The San Andreas, Imperial, Cerro Prieto,

Algodones, and the San Jacinto Fault line all pass through areas of the Basin (Figure 1).

DUNE PROCESSES

In order to examine the possibility of the connection between the dune fields, a

discussion of the dune processes is necessary.

Sand dunes are an aeolian land form. In brief, dunes are created by “localized deposition

leading to bed form nucleation, which will then fix a pattern that can propagate

downwind (Wilson 1971, as cited in Lancaster et al 1987) (Figures 2 and 3).”

Figure 2. Illustration of dune types withwind directions indicated. From McKee1979, as cited Greeley and Iverson1985.

Figure 3. Relationship between dune forms,vegetation and sand supply and wind. FromHack 1941 as cited in Greeley and Iverson, 1985

More completely, but without detailing the physics of the process, particles of sand are

lifted by the wind and transported up the windward face of a dune. Once they achieve the

crest of the dune they cascade down the slip face. The process, saltation, requires

particles of sufficiently small size and wind velocities of sufficient and consistent

strength to carry the particles to the top of the dune and over the crest. Under relatively

consistent environmental conditions, barchan dunes are an equilibrium landform: given

sand supply and winds above threshold to achieve saltation, dunes will retain their shape

as they move. The form is so stable as to maintain its shape as it intersects other slower

barchan dunes, and other land features such as gullies. The net effect of saltation is dune

migration in the leeward direction.

The rate of dune migration is determined by, the interaction of bulk transport rates, bulk

density, and height.

cr = (qc – qt)/hγp ,

In this equation, cr is the rate of advance, qc is the mass transport rate at the crest, qt is the

transport rate in the trough, h is the bed form height and γp is the bulk density (Bagnold,

1941). There is also a documented inverse ratio between slipface height and rate of

movement. The taller the slipface height, the slower the dune moves.

The existence, in a relatively small geographic area, of three distinct sand dune groups

requires a localized interplay of sand supply and wind speed and direction. The net effect

of sand supply and wind is not only dunes but also dune migration. Researchers working

in the region have investigated each of these elements.

Sand Source

Despite a wide range of early conclusions from various others studying the sources of

sand for the three dune fields, current prevailing theory is that the dunes are derived

either directly from sediments from the Colorado River (Merriam 1969) or from Lake

Cahuilla sediments, which in turn came from the Colorado River (Muhs et al 1995,

Lancaster 1995, Haff and Presti 1995).

Although the region is now desert, with the exception of the man-made Salton Sea, the

Cahuilla Basin was flooded intermittently from Late Pleistocene until the 1500s (Norris

and Norris 1961). The last filling of Lake Cahuilla has been determined to be 300 years

ago (Long and Sharp 1964). At this last flooding, the lake rose to 12m above sea level.

As the water evaporated, the lakebed was exposed leaving a supply of beach sand (Haff

and Presti 1995). 12 meters is the minimum crest elevation of the alluvial delta at Cerro

Prieto. Filling occurs in response to diversions of the Colorado River, caused by either

tectonic movement, the instability of meandering distributary channels, or infrequent

flooding (Waters 1983). Diversions in the Colorado River that filled the lakebed also

carried upper Cenozoic sediments to the region (Muhs et al 1995).

Wind Regime

Examinations into the wind regime of the region or even within the dune fields is

hampered in all cases by a lack of data, however, the existence of the dunes indicates the

presence of the consistent unidirectional winds. Long and Sharp (1964) were able to

calculate wind direction from their and Norris’ data on dune movement. They

determined that the winds operating on the Salton dune field are unimodal, narrowly

focused from the N80°E direction with a resulting sand forms drift to the southeast.

In the Algodones dune chain, Muhs et al (1995) provide a thorough examination of the

limited available historical wind data and generate sand roses with this data (Figures 4

and 5).

Figures 4 and 5. Sand roses indicatingdirection and magnitude of sand movingpotential at Yuma, Indio and El Centromeasuring stations. From Muhs et al1995.

Sand roses are weighted directional histograms illustrating the length of time that winds

exceed sand moving threshold in any direction. Wind meters in Yuma, Indio, and El

Centro, the only meters in the region with historical data of any kind, provide evidence of

a wind system arising from the southwest and seasonal variations in wind direction, but

also indicate that prevailing wind create an overall southeast drift. The movement of the

dunes in the dune field corroborates this data.

Lancaster (1995) uses the Yuma data for Gran Desierto. He suggests that the dunes in

the field appear to be significantly influenced by the same set of northwesterly winds that

effect Yuma. However, he also examined wind data from Puerto Penasco at the

southeastern edge of the dune field. From this data point, Lancaster reports on a

competing wind pattern from the southeast that impacts the Gran Desierto (Figure 6).

Figure 6. Sand roses illustrating prevailingwinds in the region of Gran Desierto field.From Lancaster 1987.

The confluence of these two wind regimes creates the star dunes evident in the center of

the dune field and the northward moving crescentic dunes.

Migration

Rate of migration for the dune fields is the third element that may be useful in examining

the dune field relationship as well as illuminating their differences. Ceteris paribus, one

would expect similar rates of migration for all the dune fields. Dunes in the dune fields

have been examined for their rates of migration by several researchers. Long and Sharp

(1964) as well as several other researchers calculated the speed of dunes at the Salton

Sea. Their research indicated significant movements over a period of study. The dunes

moved an average of 236.2m/y between 1941 and 1956 and an average of 175.3m/y

between 1956 and 1963. Haff and Presti (1981) added their own data to the data and

found that during the period of 1963 to 1981, movement is 16.2m/y. Sharp (1979)

measured the much larger slipfaces in Algodones and determined their average speed to

be 42 cm / year. It is unclear whether the rate of migration bears out the theory of

slipface movements being related to height and bulk of dunes or whether the dunes are

stabilizing. Blount and Lancaster (1990) conclude, “the low rates of sediment generation

and transport in the modern Gran Desierto suggest that it is in a period of geomorphic

stability, a situation that has probably existed during much of the late Holocene” (p728).

The research on the rate of migration displays a pattern of diminishing speed and

increasing stability in the series of dune fields from west to east, not similar rates as

might be expected

DUNE FIELDS

The consistency of sand source and wind regime over the broader region of the Cahuilla

Basin suggests that these dune fields should be related to each other. However, the varied

migration rates and the addition of conflicting wind regimes indicate a more complicated

relationship between the fields. Each region of dunes provides clues to the connections

between the fields and each has some unique characteristics related to its position in the

Cahuilla Basin (Figures 7 and 8).

Figure 7. Satellite image of the Salton Searegion depicting the northern portion of theCahuilla Basin. Fromhttp://aria.arizona.edu/browse/nalc/p039r037/19920630/lbrowse.jpg

Figure 8. Satellite image of Gran Desierto DuneField and the southern end of the Cahuilla Basin.Fromhttp://aria.arizona.edu/browse/tm/p038r038/19970221/lbrowse.jpg

Salton Sea Dune Field

The Salton Sea dune field lies southwest of the Salton Sea, south of Salton City (Figure

9).

Figure 9. A regional mapillustrating the location ofthe Salton Sea dunes inthe region From Norris1966.

The field covers approximately 8 km2 (Long and Sharp 1964). It is most northeast of the

three dune fields present in the Cahuilla Basin.

The surface of the dune field is a largely, flat slightly sloping surface made up

predominantly of concretionary sandstones and siltstones of the non marine Pliocene

Palm Springs and Borrego formations with some Lake Cahuilla clays (Haff and Presti

1981). Stream channels bisect the region, and the gullying observed is presumed to be

more recent than the last filling of Lake Cahuilla (Norris 1966).

In 1964 study, there were 47 barchan dunes (Figure 10) including one remaining barchan dune

(Long and Sharp 1964) from three observed in 1909 at the Tule Wash (Mendenhall as cited in

Norris 1966).

Figure 10. Map illustratingthe position of the barchandunes at Salton Sea as of1956. From Long and Sharp1966.

The now solitary Tule Wash barchan is believed to be part of the Salton Sea dunes

(Norris 1966) however by 1981 it appeared to have dissipated entirely. Haff and Presti

(1981) noted the presence of a total of 70 dunes in 1981 and they describe them as

distorted barchans, dune complexes, parabolic dunes, and vegetated dunes rather than the

simple series of barchans seen in previous studies.

As the furthest west in the series of dunes in the Cahuilla Basin, the conditions governing

initiation of the Salton dunes and their dissipation are useful when trying to connect the

three fields. Haff and Presti (1981) suggest that the exposure of the lakebed and strong

westerly winds present an ideal set of conditions for barchan dune formation. Simple

desiccation of the lakebed may have been sufficient when combined with the wind

regime to initiate the formation of the barchan dunes, which unlike parabolic dunes do

not require vegetation anchors for initiation.

The change over the period of study for this dunes at Salton Sea from strong simple

barchans to parabolic and vegetated dunes may indicate that the dune field is dying. As

a relatively stable equilibrium form in the presence of certain conditions, any change in

those conditions is reflected in the dune field. Norris (1964, 299) suggested that,

excluding man’s interference, “there is no reasons the dune field should not continue

indefinitely.” However, Haff and Presti (1981) provide ample evidence in the

morphology and distribution of the dunes that suggests that reduced sand supply is

affecting the western portion of the dune field: there are no dunes of significant size or

active slip faces to the west of the power lines where there were previously several

smaller dunes and one medium size dune that was new since 1956; the dunes are

diminishing in size, and nascent dunes are not developing to full formation; other dunes

are dying out before they reach the Salton Sea and the number of barchan dunes is nearly

half what it had been in previous studies. The distribution of the dunes in the field is

atypical of an active dune field, displaying large separations between dunes at the upwind

side of the field and crowding downwind (Figure 11).

Figure 11. Photo ofSalton dunes lookingnorth, illustrating theinversion of anticipateddune field structure.From Haff and Presti1995.

In a usual formation, as upwind dunes merge or dissipate, the downwind dunes continue

unaffected gaining sand from the upwind dunes. Although the reason for the dissipation

of the dunes is not known, Lancaster (1992) states that a decrease in sand supply is not

necessarily a limited factor, citing other dune fields without sand supply sources that

display active migration.

The Salton Sea dunes, as the first set of dunes in the Basin, provide initial expectations

for the other two dune fields. Given the same specifics of sand supply and wind regime,

similar structures should obtain in the other fields.

Algodones Dune Field

The Algodones Dune field is the middle of the three dune fields present. It lies on an

alluvial apron, sloping gently southwest from the Chocolate and Cargo Muchado

Mountains (Sharp 1979) on the southeastern border of the Cahuilla basin (Figure 12).

Figure 12. Satellite photo showing the position of the Algondones dune field in relationto the Salton Sea, and agricultural lands in the Cahuilla Basin.

The chain is approx. 64.4 km long and 4.8 – 9.6 km wide (Norris and Norris 1961).

Given the presence of a similar wind regime and ample sand supply from the same

lakebed as the Salton dunes, it might be anticipated that Algodones would exhibit the

same formation. In a way it does. Morphologically, the dune field is very complex, but

is generally accepted to be a chain of barchans or imperfect mega barchans showing

increasingly more distinction from north to south. Norris labels the entire dune mass as a

chain of coalescing barchan because of the orientation of the slip faces to the dune field.

The field also exhibits the typical formation of barchan fields notably reversed at the

Salton Sea field; the dunes nearest the sand source are less distinctive and the sand free

depressions are larger and more distinct the farther away from the sand source (Figure

13).

Figure 13. Aerial photo ofAlgondones dunes illustratingdifferent dune types. FromMuhs et al 1995.

Earlier descriptions by Norris and Norris (1961) divide the dune field into three parts of

progressively more distinct dune features. The first most northern section of the field is

composed of simple ridge dunes. The central portion is composed of the slip face ridges,

and the southern most portion of the dune field is made up of parallel ridges of slip faces

interspaced with sand free depressions at approximately 152.4m intervals. The southern

end has large sand free hollows marked by swarms of smaller barchans (Norris 1965).

The field ends abruptly, four miles south of the International boundary at the west side of

the Colorado flood plain. There is a peculiar feature of the hollows, there are small

barchans dunes crossing the flat surfaces of the intradune hollows. They are formed by

streamers carrying sand into the hollows and creating new barchans as well as providing

sand to older barchans (Norris 1965).

As the middle dune field in the series of three, the formation process of the Algodones

field merits examination. If, in fact, the three dune fields are related then the arrival of

sand for this chain would be expected to be related to the dissipation of the dunes at

Salton. There are conflicting theories about immediate sand source. Extensive analysis

of the Lake Cahuilla literature leads Norris (1961) to determine that the dune material

arrived on the northeast edge of the lake from a longshore current on Lake Cahuilla that

stranded materials as the lakebed jogs to the south. Sharp (1979) however suggests that

the generation of linear dunes arises from the weaker southeasterly winds from East

Mesa, feeding the dunes from the southeast rather than the northwest as the prevailing

winds and dune slip faces would indicate. Regardless of its source, Norris and Norris

(1961) determine that these dunes do not appear to be receiving any new sand and that

the frequency of wind driving sands is now much less than it has been previously.

The other consideration in the relationship of the central dune field is its initiation.

Unfortunately, the process by which this complex dune field was created is a source of

debate and is related to the issue of sand source. Researchers have suggested a series of

possibilities. Norris (1965) and Norris (1961) suggest, conventionally, that the entire

dune field arises from the late Pleistocene conditions of a greater prevalence of strong

northwesterly winds. Sharp (1979) on the other hand, hypothesizes that the majority of

the sand supply is from the East Mesa and as the sand is supplied, perpendicular to the

orientation of the dune field, it is moved to the southeast in a conveyor belt like manner

such that each dune is supplied from the dunes above it in the field and from the sands to

the east of the field. The theory, if true, suggests that the dunes and hollows were created

simultaneously. McCoy et al (1967) determine that the majority of the sand in the dune

field is contained in the middle portions of the dune field, lending only further confusion

to the matter.

The lack of clarity on both the morphologic process and the immediate sand source for

the Algodones dune chain complicates the question of drawing connections between the

dune fields. However it is clear that regardless of which process is concluded, that the

different morphology of the indicates a change in the processes of the region between the

Salton dunes and the Algodones dunes.

Gran Desierto Dune Field

The Gran Desierto is the largest active dune field in North America. It covers 5,700 km2,

just inland of the northeastern shores of the Gulf of California. The Sonora Mesa, a

deltaic barrier, is the geomorphic boundary to the west, and the Cenozoic shield volcanic

complex of the Sierra Pinacate is the northeastern barrier (Lancaster et al 1987).

As the south and easternmost dune field in the Basin, with similar deltaic sand sources,

and prevailing wind structure, it should be anticipated to share a morphology and

distribution structure with the Salton Sea, however, taking a cue from the increasing

complexity of form exhibited by the Algodones field, the Gran Desierto is another more

complex dune field. There are three main types of sand forms: sand sheets and zibar,

transverse or crescentic dunes and isolated star and reversing dunes (Figure 14).

Figure 14. Generalizedillustration of the differentdune types. FromLancaster et al 1987.

The two latter varieties existing in simple, complex and compound forms. Nearly 20% of

the sand sea is occupied by a form of crescentic dunes and there are multiple groupings of

transverse and barchanoid dunes. Although the morphology of the field is anomalous

when compared to Salton and Algodones, Lancaster et al (1987) indicate that the

morphology of the dune field is similar to that of other sand seas with larger complex

dunes in the center and progressively smaller dunes at the margins with sand sheets and

areas of localized barchanoid dunes at the outermost edges.

The parameters governing the morphological structure of the dune and the dune fields

have changed. Using evidence of dune form, Lancaster suggests the widespread

occurrence of star and reversing dunes indicate that the sand sea exists within a

transitional area between bi-directional and complex wind regimes. If it were simply a

matter of converging wind regimes, it might be anticipated that the dunes in the field

would mirror each other around the star dune populated center. There is a more

complicated system at work. Sand samples taken by Blount and Lancaster (1990, 725)

indicate that each of the dune regions is composed of sands that are texturally and

compositionally distinct. “It appears that the Gran Desierto sand sea is not a single,

integrated aeolian depositional system, but a series of partly isolated aeolian

depocenters.” They go on to suggest that this is created by pulses of supply from

different sand sources, which Lancaster in later work examines more thoroughly. In

1992, through extensive examination of the stratigraphy and mineralogy, Lancaster

determines there are multiple generations of accumulation in the Gran Desierto and the

morphology of the sand sea is created by either overlapping generations or an

accumulation of different generations. He identifies three sand sources, the fluvial and

deltaic sediments of the Colorado River, the beaches of the Gulf of California, and

alluvial fans from the Pinacate volcanic complex. Research in the Gran Desierto has

illuminated the multiplying variables that create a significantly more complex dune field.

The complexity of the Gran Desierto dune field appears to be a result of a completely

altered set of geomorphic parameters than exist at the north end of the Basin. There is

evidence however, that some of the initial more northern processes still remain. Most

striking in the dune formations is that after the segment of the sand sea populated by the

star and reversing dunes, there is a large stretch of crescentic dunes that is similar in form

to the dune field at Algodones, and with similar orientation. However unlike the dunes at

Algodones, this segment of dunes exhibit the same clustering at the leeward end that is

seen in the Salton dunes. The sand source for these dunes is determined to be the same

Colorado river sediments (Lancaster 1992) that are generally accepted to be sand sources

for the other two dune fields in the Basin.

The form of the Gran Desierto and its dunes represent a significant departure from the

more simple structures further north in the Cahuilla Basin. More complex sand sources

and wind regimes create a dune field with a range of dune forms. However the

reappearance of a set of dunes in the field more like those seen in Algodones suggest the

continued presence of the same wind regime and sand conditions.

GEOGRAPHIC BARRIERS

Given similar sand supply sources and a wind regime that appears to persist over the

extent of the basin, with varying results, it is necessary to examine other geographic

barriers to the movement of dunes and sand. Each of the dune fields in the Basin has a

geographic barrier that potentially impinges on sand movement. The Salton Sea and Tule

Wash dunes have as their eastern terminus, the Salton Sea, which absorbs and stabilizes

the dune at the point of impact. The deformation and stabilization of the dune results in

the end of its equilibrium form and consequently its movement. There has also been an

increase in gullying in the lakebed that also makes it increasingly difficult for the dunes

to survive (Haff and Presti 1981). The Algodones dune chain is ended by the Colorado

River flood plain (Norris and Norris 1961), suggesting the sands are washed into the Gulf

of California by the river. The Gran Desierto ends at approximately at the Gulf of

California, another obvious fluvial barrier. These physical barriers may be reason for the

separation between the dune fields.

There are also some man made features that intersect the dune fields. At Salton, Haff and

Presti (1981) identify sand-trapping, flood control levees west of the dune field as a

possible culprit in the premature death of some of the sand dunes. They also suggest that

portions of the field may have been bulldozed while the area was part of a military base.

Furthermore, although the filling of the basin was a natural effect of a shift in the

Colorado River channel, the present incarnation of the Salton Sea is man made and

supported. At Algodones, there are two highways, railroad tracks and the All American

and Coachella canals intersecting the dune field (Figure 15).

Figure 15. Illustration of thephysical and man made featuresintersecting Algodones dunefield. From Sharp 1979.

Algodones is also bounded on several sides by agricultural in production, and Muhs et all

(1995) suggest that adjacent dunes on East Mesa have been stabilized by human impact

on groundwater levels. It is unclear from the data available, what impact, if any these

man made changes to the landscape have on the dune fields.

CONCLUSIONS

The Salton Sea, Algodones and Gran Desierto dune fields, three distinct dune fields in the

ancient Lake Cahuilla Basin, hint at being related. Sedimentological examinations reveal

that they share a common sand source in the Colorado River sediments. Limited data on

wind conditions indicate a sustained wind regime at work throughout the extent of the

Basin, which is corroborated by dune form in all three fields. However while it might be

anticipated that a similar morphology and structure would result, each of the dune fields

displays distinctly different dune types, rates of movement and size of the dune field.

The Salton dunes field is characterized by a series of barchan dunes, initially well spaced

and distinct and clustering together towards the Salton Sea. The Algodones dune field is

an elongated field with complex mega barchans with mini barchans in between. The

Gran Desierto dune field is a complex of multiple dune forms: barchan, crescentic and

star dunes. Although further research is indicated, it is clear that some measure of the

difference between the fields is created by the introduction of competing wind regimes

and additional sand sources, but that vestiges of the wind and sand elements continue to

exert an influence on all three dune fields. Geographic barriers may be responsible for

the modern separations between the dune fields.

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Blount, G., and N. Lancaster. 1990. Development of the Gran Desierto Sand Sea,Northwestern Mexico. Geology 18(8): 724 – 728.

Greeley, R. and J. Iverson. 1985. Wind as a Geological Process: on Earth, Mars,Venus, and Titan. New York : Cambridge University Press, 1985.

Haff, P. and D. Presti. 1995. Barchan Dunes of the Salton Sea Region, California. InDesert Aeolian Processes, ed. Vatche P. Tchakerian, 153 – 177. London:Chapman and Hall.

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Lancaster, N. 1992. Relations Between Dune Generations in the Gran Desierto ofMexico. Sedimentology 39(4): 505-515.

__________. 1995. Origin of The Gran Desierto Sand Sea: Sonora, Mexico: Evidencefrom Dune Morphology and Sedimentology. In Desert Aeolian Processes, ed.Vatche P. Tchakerian, 11 - 37. London: Chapman and Hall.

Long, J. and R. Sharp. 1964. Barchan Dune Movement in Imperial Valley, California.Geological Society of America Bulletin 75: 149-156.

McCoy, F. Jr., W. Nokleberg, and R. Norris. 1967. Speculations on the Origin of theAlgodones Dunes, California. Geological Society of America Bulletin 78 (4):1039 – 1044.

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Muhs, D., C. Bush, S. Cowherd and S. Mahan. 1995. Geomorphic and GeochemicalEvidence for the Source of Sand in the Algodones Dunes, Colorado Desert,Southeastern California. . In Desert Aeolian Processes, ed. Vatche P. Tchakerian,37 - 74. London: Chapman and Hall.

Norris, R. and K. Norris. 1961. Algodones Dunes of Southern California. GeologicalSociety of America Bulletin 72(4): 605-620.

Norris, R. 1966. Barchan Dunes of Imperial Valley, California. Journal of Geology 74:292-306.

Sharp, R. 1979. Intradune flats of the Algodones Chain, Imperial Valley, California.Geological Society of America Bulletin, I 90(10): 908 – 916.

Waters, M. 1983. Late Holocene Lacustrine Chronology and Archeology of AncientLake Cahuilla, California. Quaternary Research 19: 373-387.