LATE QUATERNARY GLACIAL AND PERIGLACIAL DEPOSITS IN THE SNAKE RANGE, EAST-CENTRAL NEVADA

The Snake Range is located in east central Nevada and is within the boundaries of the Basin and Range physiographic province. The entire region experienced Cenozoic extension resulting in extensive normal faulting. Along these roughly north-south-trending faults, mountains were uplifted and valleys down-dropped, producing horst and graben topography. The Snake Range is an uplifted horst bounded to the east by Snake Valley and to the west by Spring Valley. Topographically high regions like the Snake Range are found throughout the Basin and Range province and produce drastically different microclimates from surrounding low lying valleys. Such microclimates provide refuge for the only remaining active rock glacier in the interior Great Basin. Thus, the climate in the high valleys of the Snake Range is the closest modern analog we have for Late Quaternary climatic conditions.

It has long been recognized that the Snake Range was glaciated during the Late Quaternary. Early explorers (Gilbert, 1875; Simpson, 1876; and Russell, 1884) first described glacial features in the Snake Range, and subsequent authors have continued to substantiate their reports (Weldon, 1956 and Kramer, 1962). However, little research has been conducted on the glacial history and paleoclimate of the Snake Range since this early reconnaissance work (Piegat, 1980, Osborn and Bevis, 1997, Osborn, 1988, Osborn, 1990).

This study presents a detailed 1:24,000 scale map of glacial and periglacial deposits in the Snake Range. This includes the location and morphometric parameters of cirques, moraines, rockglaciers, and permafrost features. Preliminary relative age constraints have been developed for prominent glacial deposits based on stratigraphic position and degree of modification Blackwelder, (1931), Sharpe, (1938), Birkeland, (1964, 1974), and Wayne, (1984).