Neoproterozoic Glaciation in Antarctica?

Arizona State University, Scottsdale AZ

Investigators

Abstract

Intellectual Merit: The assignment of the PI to the role of Chief Scientist at the Central Transantarctic Mountains field camp by the Office of Polar Programs has presented the PI with the opportunity to re-examine a unique geological locality at the head of Nimrod Glacier. During the 1985-86 field season, a diamictite interpreted to be of glacial origin was discovered by the PI on the Cotton Plateau. Relative dates indicated that the diamictite is of Neoproterozoic age. It is believed that this is the first evidence of Neoproterozoic glaciation in Antarctica. During the 1985-86 field season, the PI also discovered a volcanic rhyolite at Cotton Plateau interbedded with the sedimentary sequence containing the diamictite. In this proposal, the PI proposes to sample the rhyolite for U-Pb analyses on zircons to provide an age for the diamictite and allow for correlation of this deposit with the global Neoproterozoic glacial subdivisions. Detailed examination of rocks in the vicinity of the diamictite will also be undertaken to identify additional localities with a glacial affinity, thus our understanding of Antarctica?s role during this important interval of Earth history. Broader impacts: A student currently working on a M.S. thesis on rocks collected in the Transantarctic Mountains will be involved in the fieldwork and follow up lab work. The proposed field work will give a broader context for the thesis work. Because the field work will be conducted from the CTAM camp, the student will have the opportunity to interact with a broad range of other geologists. Scientifically, the Neoproterozoic glaciation is currently a research theme of great international interest and the ability to demonstrate and accurately date Neoproterozoic glaciation in Antarctica will have significant scientific impact.