| Briones Formation | |
|---|---|
| Stratigraphic range: Miocene | |
| Type | Geologic formation |
| Underlies | San Pablo Formation |
| Location | |
| Region | Contra Costa County, California |
| Country | United States |
| Type section | |
| Named for | Briones Hills |
The Briones Formation is a Late/Upper Miocene epoch geologic formation of the East Bay region in the San Francisco Bay Area, California.[1]
It is found in western Contra Costa County.[1]