9417810 Phillips The end of the last glaciation was accomplished by a series of major and abrupt climatic events. It is clear that changes in the atmospheric transport of water vapor played a key role in the deglacial process. Although these events apparently resulted in a global secession of glacial conditions, the details of the sequence of events is poorly known outside the North Atlantic region. In this project we propose to apply new geochronological and paleohydrological methods to the interpretation of glacial and lacustrine data in a single, closed drainage basin: the paleo-Owens River system in the western Great Basin. We will apply mass spectrometric U/Th and cosmosgenic 36Cl dating to refining the existing chronology for lacustrine deposits and shorelines in the terminal basins. This chronology will be compared with one derived from cosmosgenic 36Cl and carbon-14 for glacial deposits and surfaces in the eastern Sierra Nevada, at the headwaters of the Owens River. These new and refined chronologies will allow the sequence of events for the glacial and lacustrine systems to be compared with each other. The combined sequence will then be quantitatively interpreted in terms of climatic driving forces, using a transient numerical energy and mass balance model. Finally, the reconstructed climatic history can be compared with recent ice core and marine sediment records of global conditions to assess how the global events were reflected by changes in temperature and water vapor transport in a continental setting.
