The Paleohydrology of the Sonora Junction Region, CA as Recorded in Pleistocene Deposits, Dated by Multi-Parameter Dating Techniques

Currently, runoff from precipitation in the Sonora Junction region flows into the West Walker River drainage, and continues north to Antelope Valley. The distribution of early to late Pleistocene deposits, meltwater channels at the headwaters of Long, and Sario Canyons, and at Devils Gate, suggest that the West Walker drainage has been diverted into the East Walker drainage in response to landforms resulting from past climatic influences (Clark, 1967). The position and extent of the geologic features resulting from the West Walker River Glacier, tectonics, and fluvial processes have left a defining legacy delineating the hydrologic evolution of the basin. Multi-parameter relative dating of Burcham Flat, Wheeler Flat, and the terraces along the Little Walker River are suggestive that as recent as during Tahoe time meltwater may have been diverted east through Devils Gate. This study compares soil development and multi-parameter relative weathering criteria of the four most prominent right lateral/end moraines of the West Walker River Glacier, and the fluvial terraces to the east. The findings of this study suggest the West Walker Moraine suite ages to be correlative with: Tahoe, Tahoe, Tioga?, and Tioga, from oldest to youngest. The terraces along the Little Walker River are strath terraces of Tioga age, while on Wheeler Flat a thin Tahoe age strath overlies a much older deposit, likely Walker (ca. 550 ka) in age. The age of the Walker deposit is based on the stratigraphic position of a tephra correlated with the Rockland tephra (Sarna-Wojcicki, 2003).