Soda-Avawatz Fault, eastern Avawatz Mountains

This is a view to the southwest from the top of the piedmont on the eastern side of the Avawatz Mountains, ~25 km northwest of Baker, CA. In the foreground, from right to left, are the Avawatz Mountain Front, composed of Precambrian crystalline metamorphic rocks, a narrow pediment developed on these metamorphic rocks, a sliver of marble juxtaposed against the pediment, and an old (probable middle to late Pleistocene) alluvial fan deposit. The marble is in fault contact with the crystalline metamorphic rock and these older lithologies are buried by the alluvial fan deposit. The fault that juxtaposes the marble against the metamorphic rocks is the northwestern end of the Soda-Avawatz Fault Zone, a northwest-trending right-lateral strike slip fault that makes up the eastern most boundary of the Quaternary Eastern California Shear Zone. This photo was taken while conducting surficial geologic mapping of the Avawatz Mountains piedmont. This is one component of several different surficial, bedrock, and geophysical mapping activities in the Mojave Desert in order to better understand the tectonics of the Eastern California Shear Zone, which accommodates between ~20 and 25% of the relative motion between the Pacific and North American plates. 

In the middle ground, on the left are the Halloran Hills and on the right the northern end of the eastern Soda Mountains, and behind them Silver Lake Playa, which is part of the terminal basin for the Mojave River. The high topography making up the skyline is the Providence Mountain Range, in the Mojave National Preserve.