Glaciations of the Sierra Nevada, California, USA

The Sierra Nevada is a c. 4000 m range of mountains paralle1 to the North American Pacific Coast that was repeatedly glaciated during the climatic fluchrations of the Quatemary. The glacial record on the eastem side of the range includes eight named Pleistocene glaciations and stadials: McGee, Sherwin, Casa Diablo, Mono Basin, Tahoe, Tenaya, Tioga and Recess Peak, as well as the Neoglacial Matthes (Little Ice Age) advance (a11 in order of decreasing age). Studies of lake-sediment cores show that the actual number of glacial advances and retreats was much greater than nine, aithough not all glaciers left drift that has been preserved andlor identified in the mountains themselves. End-moraine positions and equilibrium-line altitude (ELA) depressions of the largest glaciers were about the same, regardless of age. Recent efforts to date glacial deposits numerically have added detail to our understanding of Sierra Nevada glacial chronology. However, except for the late-Pleistocene advances, the results may serve only as limits to the age of the glaciations, because of erosion and other geological complexities.