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Mission Valley Formation facts for kids

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Mission Valley Formation
Stratigraphic range: Paleogene
Type Geologic formation
Underlies Pomerado Conglomerate
Overlies Stadium Conglomerate
Thickness 0–60 metres (0–197 ft)
Primary sandstone
Region San Diego County, California
Country United States
Type section
Named for Mission Valley, San Diego

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


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 0–60 metres (0–197 ft).

It overlies the Stadium Conglomerate formation, and underlies the Pomerado Conglomerate formation.


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.

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