Skip to main content
U.S. flag

An official website of the United States government

All Maps

Explore all USGS Maps and refine your search by type, topic, year, location, and advanced search. 

Filter Total Items: 9586

Geology, tephrochronology, radiometric ages, and cross sections of the Mark West Springs 7.5' quadrangle, Sonoma and Napa counties, California Geology, tephrochronology, radiometric ages, and cross sections of the Mark West Springs 7.5' quadrangle, Sonoma and Napa counties, California

The purpose of this geologic map is to provide a context within which to interpret the Neogene evolution of the active strike-slip fault system traversing the Mark West Springs 7.5' quadrangle and adjacent areas. Based on this geologic framework, the timing and total amounts of displacement and the Neogene rates of slip for faults of the right-stepover area between the Healdsburg and...
Was this page helpful?