Punchbowl Formation

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.[2][3]

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
Type	Formation
Underlies	Crowder Formation[1]
Overlies	Paradise Springs Formation
Lithology
Primary	Conglomerate, sandstone
Other	Mudstone
Location
Coordinates	34.0°N 118.2°W
Approximate paleocoordinates	33.4°N 114.4°W
Region	Los Angeles County, California
Country	United States
Extent	San Gabriel Mountains
Type section
Named for	Devil's Punchbowl
Named by	Noble
Year defined	1953
Punchbowl Formation (the United States) Punchbowl Formation (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.[2] 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.[4]

The Devil's Punchbowl drainage flows into Sandrock Creek, a tributary of Big Rock Creek, which disappears into the Mojave Desert.[2]

Fossil content

The uplifted formation preserves fossils dating back to the Neogene period of the Cenozoic geologic era,[3] formed during the lower Pliocene to upper Miocene Ages (~5-10 million years ago).[2][5]

Artiodactyls

• Aepycamelus alexandrae[6]
• Bouromeryx americanus[7]
• Brachycrus cf. buwaldi[8]
• Dyseohyus fricki[6]
• Pseudoparablastomeryx cf. scotti[8]
• Brachycrus sp.[6]
• Plioceros sp.[8]
• Antilocapridae indet.[9]
• Blastomerycinae indet.[8]
• Camelidae indet.[8]
• ?Merycoidodontidae indet.[8]
• Tayassuidae indet.[8]

Perissodactyls

• Archaeohippus mourningi[8]
• Parapliohippus cf. carrizoensis[8]
• Pliohippus cf. tehonensis[8]
• Scaphohippus intermontanus[8]
• S. sumani[6]
• Cormohipparion sp.[10]
• ?Archaeohippus sp.[8]
• Equini indet.[8]
• Hipparionini indet.[8]
• Rhinocerotidae indet.[8]

Carnivora

• Borophagus cf. secundus[8]
• Leptarctus ancipidens[9]
• Plionictis sp.[8]

Rodents

• Petauristodon sp.[8]
• Sciuridae indet.[9]

Turtles

• Gopherus depressus[8]

Gallery

• 
  The Devil's Punchbowl
• 
  Formation at Devil's Punchbowl
• 
  Formation in the Angeles National Forest
• 
  Formation at Sturtevant Falls

See also

• List of fossiliferous stratigraphic units in California
• Neogene period in California
• Paleontology in California
• Diligencia Formation
• Mint Canyon Formation
• Plush Ranch Formation

References

1. Thomas W. Dibblee (1967). "Areal geology of the western Mojave Desert, California" (PDF). Professional Paper. 522: 49. doi:10.3133/PP522. ISSN 2330-7102. Wikidata  Q57842316.
2. UCB−Seismo.berkeley.edu: Field Guide to the Punchbowl Fault Zone at the Devil's Punchbowl Natural Area . 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

• Coffey, Kevin T.; Raymond V. Ingersoll, and Axel K. Schmitt. 2019. Stratigraphy, provenance, and tectonic significance of the Punchbowl block, San Gabriel Mountains, California, USA. Geosphere 15. 479–501.
• Pagnac, D. 2006. Scaphohippus, a new genus of horse (Mammalia: Equidae) from the Barstow Formation of California. Journal of Mammalian Evolution 13. 37–61.
• Woodburne, M. O. 2005. A new occurrence of Cormohipparion, with implications for the Old World Hippotherium Datum. Journal of Vertebrate Paleontology 25. 256–257.
• Liter, M., and D. Prothero. 2003. New dromomerycids (Mammalia: Artiodactyla) from the middle Miocene Sharktooth Hill Bonebed, California, and the systematics of the cranioceratinins. Journal of Vertebrate Paleontology 23. 72A.
• Wagner, H. M., and R. E. Reynolds. 1983. Leptarctus ancipidens (White) (Carnivora: Mammalia) from the Punchbowl Formation, Cajon Pass, California. Bulletin of the Southern California Academy of Sciences 82. 131–137.
• Woodburne, M. O., and D. J. Golz. 1972. Stratigraphy of the Punchbowl Formation, Cajon Valley, southern California. University of California Publications in Geological Sciences 92. 1–72.

External links

• Los Angeles County: Devil's Punchbowl Natural Area website
• Devil's Punchbowl photos gallery — geology + flora