Mission Valley Formation

The Mission Valley Formation is a marine sandstone geologic formation in the Mission Valley region of southwestern San Diego County in Southern California.[1][2]

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

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.[1] The Mission Valley Formation thins from the west to the east, with a maximum thickness of 0–60 metres (0–197 ft).[1]

It overlies the Stadium Conglomerate formation, and underlies the Pomerado Conglomerate formation.[1]

Fossils

It preserves fossils dating back to the Paleogene period of the Cenozoic Era.[3] The formation's rocks can contain a molluscan fauna in the western and central exposures and a land-mammal fauna in the eastern exposures.[1]

See also

• Geology of San Diego County, California
• Paleogene Period in California
• List of fossiliferous stratigraphic units in California
• Paleontology in California

References

1. Kennedy, Michael P. (1975). Geology of the San Diego metropolitan area, California. California Division of Mines and Geology.
2. Geiconsultants.com: Geologic Formations of Western San Diego County, by Jeffrey D. Brown, R.G., C.E.G. − circa 1996.
3. Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Archived from the original on 31 July 2014. Retrieved 8 July 2014.

Further reading

• "General Plan Final Program EIR: 3.11 Paleontological Resources" (PDF). City of San Diego.