TY  - RPRT
TI  - Preliminary geologic map emphasizing bedrock formations in Contra Costa County, California: A digital database
AU  - R. W. Graymer
AU  - David Lawrence Jones
AU  - Earl E. Brabb
PY  - 1994
DO  - 10.3133/ofr94622
UR  - https://pubs.usgs.gov/publication/ofr94622
ID  - ofr94622
ER  -