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dc.contributor.authorLong, Austin*
dc.creatorLong, Austin,1936-en_US
dc.date.accessioned2011-11-28T13:20:39Z
dc.date.available2011-11-28T13:20:39Z
dc.date.issued1966en_US
dc.identifier.urihttp://hdl.handle.net/10150/190942
dc.description.abstractA stratigraphic radiocarbon study at the Wilicox Playa and vicinity in Cochise County, southeastern Arizona has revealed a sedimentary sequence reflecting the lake level chronology of ancient Lake Cochise. The lower green clay was deposited in a lake at least 30 miles long from before 30,000 years ago until about 13,000 years ago. A marl formation which began depositing about 25,000 years ago and continued until the lake diminishe to about its present state 13,000 years ago, indicates a warm, moist climate at that time. The period from 13,000 B.P. (before present) and 11,000 B.P. was one of alluvial deposition north of the playa and channel cutting east of the playa. An upper green clay, 6 to 8 inches thick, represented the final phase of Lake Cochise, lasting from 11,500 B.P. until 10,500 B.P. A thin marl layer was deposited during this phase, indicating warm moist conditions again. The lake rapidly receded, some playa sediments deflated from the surface, and dunes formed north of the playa. Preliminary studies of two playas near Lordsburg, New Mexico and one at the San Augustin Plains, New Mexico, indicate these fluctuations were responding to a general climate change rather than isolated tectonic disturbances. The climate chronology concluded from this study is consistent with known climatic variations in the world.
dc.language.isoenen_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.subjectHydrology.en_US
dc.subjectGeology, Stratigraphic -- Pleistocene.en_US
dc.subjectGeology -- Arizona -- Cochise County.en_US
dc.subjectPlayas -- Arizona.en_US
dc.titleLate Pleistocene and recent chronologies of Playa lakes in Arizona and New Mexicoen_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.typetexten_US
dc.contributor.chairDamon, Paul E.en_US
dc.identifier.oclc213889552en_US
thesis.degree.grantorUniversity of Arizonaen_US
thesis.degree.leveldoctoralen_US
dc.contributor.committeememberSmiley, Terah L.en_US
dc.contributor.committeememberLance, John F.en_US
dc.contributor.committeememberCorrin, Myron L.en_US
dc.contributor.committeememberForster, Leslie S.en_US
thesis.degree.disciplineGeologyen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.namePh. D.en_US
dc.description.notehydrology collectionen_US
refterms.dateFOA2018-06-18T21:44:20Z
html.description.abstractA stratigraphic radiocarbon study at the Wilicox Playa and vicinity in Cochise County, southeastern Arizona has revealed a sedimentary sequence reflecting the lake level chronology of ancient Lake Cochise. The lower green clay was deposited in a lake at least 30 miles long from before 30,000 years ago until about 13,000 years ago. A marl formation which began depositing about 25,000 years ago and continued until the lake diminishe to about its present state 13,000 years ago, indicates a warm, moist climate at that time. The period from 13,000 B.P. (before present) and 11,000 B.P. was one of alluvial deposition north of the playa and channel cutting east of the playa. An upper green clay, 6 to 8 inches thick, represented the final phase of Lake Cochise, lasting from 11,500 B.P. until 10,500 B.P. A thin marl layer was deposited during this phase, indicating warm moist conditions again. The lake rapidly receded, some playa sediments deflated from the surface, and dunes formed north of the playa. Preliminary studies of two playas near Lordsburg, New Mexico and one at the San Augustin Plains, New Mexico, indicate these fluctuations were responding to a general climate change rather than isolated tectonic disturbances. The climate chronology concluded from this study is consistent with known climatic variations in the world.


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