San Joaquin Formation

The San Joaquin Formation is a Pliocene epoch geologic formation in the lower half of the San Joaquin Valley in central California.

Geology
With the underlying Etchegoin Formation, it is associated with the numerous oil fields in the central and southern San Joaquin Valley. It is overlaid by the Tulare Formation.

It preserves fossils dating back to the Neogene period of the Cenozoic Era.