PIs will analyze Neogene climatic and depositional evolution of the eastern Basin and Range (US) by integrating paleoecologic, stratigraphic and seismic data from the Great Salt Lake. Source of material is Amoco and includes cores, cuttings, samples, and seismic lines. ?PIs have funding from TEctonics program for basin analysis aspects of project.! Primary objective is to test hypotheses of climate change recently proposed for Neogene of western North America by 1) documenting onset and development of cool, dry climate in Neogene, 2) developing chronology through radiometric dates on tephras and basalts, 3) producing detailed climate record from a single region, for a time now known only from overlapping segments from diverse deposits. They will also a) develop a chronology for Neogene evolution of vegetation in the Great Basin, b) produce Neogene paleolimnologic study of GSL, c) study onset and evolution of glacial/interglacial climatic cycles.