The Punchbowl Formation is a sedimentary

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

in the northern

San Gabriel Mountains The San Gabriel Mountains ( es, Sierra de San Gabriel) are a mountain range located in northern Los Angeles County, California, Los Angeles County and western San Bernardino County, California, United States. The mountain range is part of the Tr ...

, above the

Antelope Valley The Antelope Valley is located in northern Los Angeles County, California, and the southeast portion of Kern County, California, and constitutes the western tip of the Mojave Desert. It is situated between the Tehachapi, Sierra Pelona, and the ...

Los Angeles County Los Angeles County, officially the County of Los Angeles, and sometimes abbreviated as L.A. County, is the most populous county in the United States and in the U.S. state of California, with 9,861,224 residents estimated as of 2022. It is the ...

, southern

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

.UCB−Seismo.berkeley.edu: Field Guide to the Punchbowl Fault Zone at the Devil's Punchbowl Natural Area
. accessed 7.7.2015Punchbowl Formation
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...

.org

Geology

The sandstone beds of the formation are exposed in the walls of the

Devil's Punchbowl The Devil's Punch Bowl is a visitor attraction and biological Site of Special Scientific Interest situated just to the east of the village of Hindhead in the English county of Surrey. It is part of the Wealden Heaths Phase II Special Protecti ...

, a scenic

gorge A canyon (from ; archaic British English spelling: ''cañon''), or gorge, is a deep cleft between escarpments or cliffs resulting from weathering and the erosion, erosive activity of a river over geologic time scales. Rivers have a natural tenden ...

within the Devil's Punchbowl Natural Area, an L.A. County park within the

Angeles National Forest The Angeles National Forest (ANF) of the United States Forest Service, U.S. Forest Service is located in the San Gabriel Mountains and Sierra Pelona Mountains, primarily within Los Angeles County, California, Los Angeles County in southern Calif ...

. Three separate faults have folded and uplifted the formation in view. The Devil's Punchbowl is a large plunging sandstone

syncline In structural geology, a syncline is a fold with younger layers closer to the center of the structure, whereas an anticline is the inverse of a syncline. A synclinorium (plural synclinoriums or synclinoria) is a large syncline with superimpose ...

, 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 The San Andreas Fault is a continental transform fault that extends roughly through California. It forms the tectonics, tectonic boundary between the Pacific Plate and the North American Plate, and its motion is Fault (geology)#Strike-slip fau ...

to the north. The Punchbowl Formation crops out in the Punchbowl Block and comprises approximately of

fluvial In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluviog ...

and

alluvial Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluv ...

conglomerates,

s, and minor

mudstone Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Mudstone is distinguished from '' shale'' by its lack of fissility (parallel layering).Blatt, H., and R.J. Tracy, 1996, ''Petrology. ...

s, which accumulated during the middle-late Miocene. A distinct basal member is middle Miocene in age. The underlying Paradise Springs and

Vasquez Formation The Vasquez Formation (Tvz) is a Formation (geology), geologic formation outcrop, cropping out at the eponymous Vasquez Rocks in southern California. The formation dates to the Late Oligocene to Early Miocene (Arikareean in the North American land ...

s 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.Coffey et al., 2019, p.480 The Devil's Punchbowl drainage flows into Sandrock Creek, a tributary of Big Rock Creek, which disappears into the

Mojave Desert The Mojave Desert ( ; mov, Hayikwiir Mat'aar; es, Desierto de Mojave) is a desert in the rain shadow of the Sierra Nevada mountains in the Southwestern United States. It is named for the indigenous Mojave people. It is located primarily in ...

Fossil content

The uplifted formation preserves

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...

dating back to the

Neogene The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...

period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

of the

Cenozoic The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configura ...

geologic era The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronol ...

, formed during the lower

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

Ages Ages may refer to: *Advanced glycation end-products, known as AGEs *Ages, Kentucky, census-designated place, United States * ''Ages'' (album) by German electronic musician Edgar Froese *The geologic time scale, a system of chronological measuremen ...

(~5-10 million years ago).L.A. County: "Geological History"
with images

Mammals

Rodents

* '' Petauristodon sp.'' * Sciuridae indet.Wagner & Reynolds, 1983

Reptiles

Turtles

* '' Gopherus depressus''

Gallery

File:DevilsPunchbowlCA.JPG, The

File:Devil's_Punchbowl_Rocks_sm.jpg, Formation at Devil's Punchbowl File:Angeles National Forest (15480513542).jpg, Formation in the

File:Sturtevant Falls (15294301478).jpg, Formation at Sturtevant Falls

References

Bibliography

* * * * * *

External links

{{Commons category, Punchbowl Formation
Los Angeles County: Devil's Punchbowl Natural Area website

— ''geology + flora'' Geologic formations of California Miocene Series of North America Miocene California Langhian Serravallian Tortonian Clarendonian Hemphillian Conglomerate formations Sandstone formations of the United States Alluvial deposits Fluvial deposits Paleontology in California Geology of Los Angeles County, California San Gabriel Mountains Angeles National Forest