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The Pleistocene fauna of the Manix Beds in the Mojave Desert, California

Citation

Winters, H. H. (1954) The Pleistocene fauna of the Manix Beds in the Mojave Desert, California. Master's thesis, California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-02032004-144346

Abstract

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The Manix Beds were deposited in a Pleistocene lake basin that occupied 200 to 300 square miles of the Mojave Desert, near the center of San Bernardino County, California. Three stages of lake deposition are recognized. Arenaceous clays and argillaceous sands, light grayish-green in color, are the predominant lithologies. The first and second lake stages are separated by interpluvial sediments; erosion occurred between the second and third stages. The total thickness of lake and interpluvial deposition in the center of the basin probably exceeded 250 feet. Except for minor faulting, which has affected even the youngest layers, the Manix Beds are essentially undefomed.

When Lake Manix first formed, the mammalian fauna included a sabre-tooth cat apparently close to Machairodus, Equus sp. cf. E. scotti, Camelops sp. cf. C. kansanus, a giant camel, and possibly a primitive species of Tremarctotherium. Therefore, an Illinoian age is suggested for the first lake stage. Tortoise and fish remains tend to corroborate this dating. This pluvial stage may be younger, but hardly older, than Illinoian as is indicated by fragmentary remains of what appears to be a small or medium-sized Bison. The Avifauna indicates a late Pleistocene, possibly Tahoe, age for the second lake stage. The molluscan fauna from this lake is possibly of Tahoe times. No vertebrate fossils have been recovered from beds of the third lake stage, but, sequentially, deposition probably took place during the Tioga subage of the Wisconsin.

Conformable beneath the Manix Beds are 300 to 400 feet of fanglomerates that are considered to be interpluvial sediments of probable Yarmouthian age. The fanglomerates overlie, with an angular unconfomity, Tertiary volcanics that have been highly sheared and deformed, probably by Pasadenan orogenic movements. The extreme coarseness, angularity, and lack of decomposition or sorting of the fanglomerates suggest their deposition during the late phases of the Pasadenan Orogeny in the Yarmouthian interglacial age.

Item Type:Thesis (Master's thesis)
Degree Grantor:California Institute of Technology
Division:Geological and Planetary Sciences
Major Option:Geological and Planetary Sciences
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Hewett, D. F.
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1954
Record Number:CaltechETD:etd-02032004-144346
Persistent URL:http://resolver.caltech.edu/CaltechETD:etd-02032004-144346
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:479
Collection:CaltechTHESIS
Deposited By: Imported from ETD-db
Deposited On:17 Feb 2004
Last Modified:26 Dec 2012 02:30

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