Soil Genesis On the Bishop Creek Moraines, Eastern Sierra Nevada, California.

Soil development and changes in soil geomorphology have been studied on a number of alpine moraine complexes of the eastern Sierra Nevada. One of these moraine sequences, the Bishop Creek Moraines, is well suited to chronosequence studies because it includes a number of well-preserved moraines representing several different glaciations. The goal of this study was to study the genesis of soils formed on these moraines and determine the geomorphic and environmental factors influencing their development. Soil morphology, surface clast cover, and moraine morphology were studied on seven of the moraines, ranging in age from 15 to 170 ka. Soils showed weak development across the chronosequence. Pedogenesis was characterized by slight increases in clay, the formation of clay lamellae, development of a vesicular horizon in an aeolian dust mantle, weathering of subsurface granitic clasts, and slight accumulations of pedogenic silica. Older moraines had gentler slopes, broader crests, and decreased surface rock cover. Soils developed along a complex pathway with intermittent periods of erosion, deposition, and soil formation. Soils formed on the Bishop Creek Moraines develop in three different parent materials: glacial till, aeolian sediments, and grus weathered from surface clasts.