A photo of bedrock.

A photo of bedrock.

Detailed Description

Older Quaternary alluvial gravels overlie weathered Franciscan bedrock along Highway 1 south of the intersection of Bolinas-Olema Road along Bolinas Lagoon. The age of the gravels is about 55,000 years based on correlation of volcanic ash found in this unit (analysis by Andrei Sarna-Wojcicki, USGS).


Image Dimensions: 900 x 675

Date Taken:

Location Taken: US