Pleistocene Lake Outburst Floods and Fan Formation Along the Eastern
ARTICLE IN PRESS Quaternary Science Reviews 25 (2006) 2729–2748 Pleistocene lake outburst floods and fan formation along the eastern Sierra Nevada, California: implications for the interpretation of intermontane lacustrine records Douglas I. Benna,b,Ã, Lewis A. Owenc, Robert C. Finkeld, Samuel Clemmense aSchool of Geography and Geosciences, University of St. Andrews, St. Andrews KY16 9AL, UK bDepartment of Geology, UNIS, PO Box 156, N-9171 Longyearbyen, Norway cDepartment of Geology, University of Cincinnati, Cincinnati, OH 45221-0013, USA dCenter for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA eInstitute of Geography and Earth Sciences, University of Wales, Aberystwyth SY23 3DB, UK Received 10 June 2005; accepted 5 February 2006 Abstract Variations in the rock flour fraction in intermontane lacustrine sediments have the potential to provide more complete records of glacier fluctuations than moraine sequences, which are subject to erosional censoring. Construction of glacial chronologies from such records relies on the assumption that rock flour concentration is a simple function of glacier extent. However, other factors may influence the delivery of glacigenic sediments to intermontane lakes, including paraglacial adjustment of slope and fluvial systems to deglaciation, variations in precipitation and snowmelt, and lake outburst floods. We have investigated the processes and chronology of sediment transport on the Tuttle and Lone Pine alluvial fans in the eastern Sierra Nevada, California, USA, to elucidate the links between former glacier systems located upstream and the long sedimentary record from Owens Lake located downstream. Aggradation of both fans reflects sedimentation by three contrasting process regimes: (1) high magnitude, catastrophic floods, (2) fluvial or glacifluvial river systems, and (3) debris flows and other slope processes.
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