Mission Valley Formation

The Mission Valley Formation is a marine sandstone geologic formation in the Mission [Valley, San Diego|Mission Valley] region of southwestern San [Diego County, California].

Geology

The formation's sandstone characteristics are: soft and friable, light olive gray, fine to medium grained, and composed mostly of quartz and potassium feldspar. The Mission Valley Formation thins from the west to the east, with a maximum thickness of.
It overlies the Stadium Conglomerate formation and underlies the Pomerado Conglomerate formation.

Fossil content

It preserves fossils dating back to the Paleogene period of the Cenozoic Era. The formation's rocks can contain a molluscan fauna in the western and central exposures and a land-mammal fauna in the eastern exposures.