Late Pleistocene alpine glacial deposits in the Pine Forest Range, Nevada

Abstract

Descriptive geology, interpretation of aerial photographs, and relative dating (RD) parameters are all used to recognize glacial deposits from two glaciations in the Pine Forest Range, northwestern Nevada. Early deposits of Onion Valley age have a less distinct morphology than subsequent Blue Lake age deposits. RD parameters useful in distinguishing between the two deposits are surface boulder frequency, percent pitted, hammerblow weathering ratio, maximum dike height, and oxidation ratio. Cluster analysis greatly facilitates RD data interpretation. Soil B horizons are present only on deposits of Onion Valley age. RD data suggest a stage order difference for the two glaciations. The Onion Valley and Blue Lake deposits are correlated with the Sierra Nevada Tahoe and Tioga deposits and the Ruby-East Humboldt Range Lamoille and Angel Lake deposits. Based on these correlations along with data from Steens Mountain and Lake Lahontan deposits, the Blue Lake and Onion Valley glaciations are estimated to be oxygen isotope stage 2 and 6 respectively.