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Punchbowl Formation

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Miocene sedimentary formation in the San Gabriel Mountains of Los Angeles County, California
Punchbowl Formation
Stratigraphic range: Mid-Late Miocene (Clarendonian-Hemphillian)
~14–8 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Outcrop of the tilted formation at the eponymous Devil's Punchbowl
TypeFormation
UnderliesCrowder Formation
OverliesParadise Springs Formation
Lithology
PrimaryConglomerate, sandstone
OtherMudstone
Location
Coordinates34°00′N 118°12′W / 34.0°N 118.2°W / 34.0; -118.2
Approximate paleocoordinates33°24′N 114°24′W / 33.4°N 114.4°W / 33.4; -114.4
RegionLos Angeles County, California
Country United States
ExtentSan Gabriel Mountains
Type section
Named forDevil's Punchbowl
Named byNoble
Year defined1953
Punchbowl Formation is located in the United StatesPunchbowl FormationPunchbowl Formation (the United States)Show map of the United StatesPunchbowl Formation is located in CaliforniaPunchbowl FormationPunchbowl Formation (California)Show map of California

The Punchbowl Formation is a sedimentary sandstone geologic formation in the northern San Gabriel Mountains, above the Antelope Valley in Los Angeles County, southern California.

Geology

The sandstone beds of the formation are exposed in the walls of the Devil's Punchbowl, a scenic gorge within the Devil's Punchbowl Natural Area, an L.A. County park within the Angeles National Forest. Three separate faults have folded and uplifted the formation in view. The Devil's Punchbowl is a large plunging sandstone syncline, where the edges of the formation have been folded upward, and the center has dipped. It was formed by the Punchbowl Fault, which is near the San Andreas Fault to the north.

The Punchbowl Formation crops out in the Punchbowl Block and comprises approximately 1,500 metres (4,900 ft) of fluvial and alluvial conglomerates, sandstones, and minor mudstones, which accumulated during the middle-late Miocene. A distinct basal member is middle Miocene in age. The underlying Paradise Springs and Vasquez Formations were formerly interpreted as either part of the basal Punchbowl Formation, or deposits in a fault-bounded sliver along the Punchbowl Fault that originated in a separate basin.

The Devil's Punchbowl drainage flows into Sandrock Creek, a tributary of Big Rock Creek, which disappears into the Mojave Desert.

Fossil content

The uplifted formation preserves fossils dating back to the Neogene period of the Cenozoic geologic era, formed during the lower Pliocene to upper Miocene Ages (~5-10 million years ago).

Mammals

Artiodactyls

Perissodactyls

Carnivora

Rodents

Reptiles

Turtles

Gallery

See also

References

  1. Thomas W. Dibblee (1967). "Areal geology of the western Mojave Desert, California" (PDF). Geological Survey Professional Paper. 522: 49. doi:10.3133/PP522. ISSN 0096-0446. Wikidata Q57842316.
  2. ^ UCB−Seismo.berkeley.edu: Field Guide to the Punchbowl Fault Zone at the Devil's Punchbowl Natural Area Archived 2016-03-05 at the Wayback Machine . accessed 7.7.2015
  3. ^ Punchbowl Formation at Fossilworks.org
  4. Coffey et al., 2019, p.480
  5. L.A. County: "Geological History", with images
  6. ^ Pagnac, 2006
  7. Liter & Prothero, 2003
  8. ^ Woodburne & Golz, 1972
  9. ^ Wagner & Reynolds, 1983
  10. Woodburne, 2005

Bibliography

External links

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