Blake, M. Clark, Jr.

About the author


Digital geologic map and map database of parts of Marin, San Francisco, Alameda, Contra Costa, and Sonoma Counties, California

This digital map database, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution of bedrock and surficial deposits in the mapped area. Together with the accompanying text file (mageo.t

Preliminary Geologic Description of the San Jose 30 X 60 Minute Quadrangle, California: A Digital Database

The San Jose 30 x 60-minute quadrangle straddles the California Coast Ranges southeast of San Francisco, and extends from west of the San Andreas fault near Santa Cruz on the southwest (long. -122°, lat. 37°) to the San Joaquin River in the Central Vall

Geologic map of the Cape Mendocino, Eureka, Garberville, and southwestern part of the Hayfork 30 X 60 Quadrangles and Adjacent Offshore Area, Northern California

This digital map database, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution of bedrock and surficial deposits in the mapped area. Together with the accompanying text file (ceghmf