Late Pleistocene dropstone record of the Wilson Creek Formation, Mono Basin, CA

TitleLate Pleistocene dropstone record of the Wilson Creek Formation, Mono Basin, CA
Publication TypeConference Proceedings
Year of Conference2001
AuthorsZimmerman SRH, Hemming SR, Tamuloni K
Conference NameGeological Society of America, 2001 annual meeting
PublisherGeological Society of America (GSA) Boulder CO United States
Conference LocationBoston, MA
ISBN Number(print) 0016-7592
Accession Number2002-057462
Keywords24 Quaternary geology, Basin and Range Province, basins, California, Cenozoic, depositional environment, dropstone, glacial environment, Glacial Geology, glaciolacustrine environment, Great Basin, ice movement, ice rafting, lacustrine environment, lake-level changes, lake sediments, Mono County California, Mono Lake, North America, paleogeography, Pleistocene, provenance, Quaternary, sedimentary basins, sediments, United States, upper Pleistocene, Wilson Creek Formation

The levels of closed lake basins of western North America's Great Basin are known to have increased substantially during the Quaternary glacial intervals. At Owens lake CA, published evidence suggests a general coincidence between Sierra Nevada glacier extent and higher lake levels. In the Mono Lake basin oversized clasts are preserved in the exposed deep lake sediments of the Wilson Creek Formation, interpreted by previous workers as ice-rafted dropstones. If they were dropped by icebergs, the presence of dropstones in the lacustrine sediments requires a coincidence between extreme glacial advance and lake level. The Wilson Creek Formation has 19 ash layers that allow detailed correlation around the Mono basin (Lajoie, 1968, unpub. Ph.D. thesis, UC Berkeley). Eighty nine 5 cm intervals, each 20 meters long, were surveyed between stratigraphic markers Ashes 7 ( approximately 25 ka) and 19 (45