Santa Susana Formation

The Santa Susana Formation is a Paleogene period geologic formation in the Simi Hills and western Santa Susana Mountains of southern California.

The formation consists largely of light-gray shale and some fine-grained shaly sandstone, with a lens of heavy conglomerates in the lower part. Small beds of limestone are also present. It is from 1000 - 1500 ft thick.

Fossil content
The Santa Susana Formation preserves fossils from the Late Paleocene to Early Eocene epochs in the Paleogene period of the Cenozoic Era. Fossilized fauna in the Santa Susana Formation is entirely different from that of underlying Martinez Formation, and has very little in common with that of the overlying Meganos Formation.