Layers of stone and tar at Carpinteria, CA

Map of California highlighting Santa Barbara County

The Carpinteria Tar Pits (also Carpinteria Oil Seeps) are a series of natural

asphalt lakes Asphalt, also known as bitumen (, ), is a sticky, black, highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product, and is classed as a pitch. Before the 20th century, the term a ...

situated in the southern part of

Santa Barbara County Santa Barbara County, California, officially the County of Santa Barbara, is located in Southern California. As of the 2020 census, the population was 448,229. The county seat is Santa Barbara, and the largest city is Santa Maria. Santa Barba ...

in southern California, USA. The Carpinteria Tar Pits are a natural asphalt lake areas similar to Tierra de Brea

Trinidad and Tobago Trinidad and Tobago (, ), officially the Republic of Trinidad and Tobago, is the southernmost island country in the Caribbean. Consisting of the main islands Trinidad and Tobago, and numerous much smaller islands, it is situated south of ...

, Lake Guanoco in

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...

and the

La Brea Tar Pits La Brea Tar Pits is an active paleontological research site in urban Los Angeles. Hancock Park was formed around a group of tar pits where natural asphalt (also called asphaltum, bitumen, or pitch; ''brea'' in Spanish) has seeped up from the gro ...

(Los Angeles) and

McKittrick Tar Pits The McKittrick Tar Pits (also McKittrick Oil Seeps and McKittrick Brea Pits) are a series of natural asphalt lakes situated in the western part of Kern County in southern California. The pits are the most extensive asphalt lakes in the stat ...

( McKittrick) both also located in the US state of California.

Geography

The Carpinteria Tar Pits are located in the southeastern extremity of Santa Barbara County about southeast of Santa Barbara in the town of

Carpinteria Carpinteria (; es, Carpintería, meaning "Carpentry") is a small seaside city in southeastern Santa Barbara County, California. Located on the Central Coast of California, it had a population of 13,264 at the 2020 census. Carpinteria is a po ...

. The area is a designated park, the Tar Pits Park, and lies within the Carpinteria State Beach area in the southern part between the ''Santa Rosa'' and the ''San Miguel'' campsites. Most of the tar pits are located along a short stretch directly on the beach and generate from the underlying

Carpinteria Offshore Oil Field The Carpinteria Offshore Oil Field is an oil and gas field in Santa Barbara Channel, south of the city of Carpinteria, California, Carpinteria in southern California in the United States. Discovered in 1964, and reaching peak production in 1969, ...

Geology

The Carpinteria Tar Pits probably date from the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided by ...

. The creation of an asphalt lake is typically the result of upwards migrations of hydrocarbons along a geologic fault. Additionally, in connection with

subduction Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the ...

pressure can be created against underlying oil

source rock In petroleum geology, source rock is rock which has generated hydrocarbons or which could generate hydrocarbons. Source rocks are one of the necessary elements of a working petroleum system. They are organic-rich sediments that may have been depos ...

. The oil moves towards the surface and slowly transforms into

bitumen Asphalt, also known as bitumen (, ), is a sticky, black, highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product, and is classed as a pitch. Before the 20th century, the term a ...

; on the way through the

lithosphere A lithosphere () is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust (geology), crust and the portion of the upper mantle (geology), mantle that behaves elastically on time sca ...

, it picks up clay and water and is cooled into asphalt.

History

The Carpinteria Tar Pits were known to the

Chumash people The Chumash are a Native American people of the central and southern coastal regions of California, in portions of what is now San Luis Obispo, Santa Barbara, Ventura and Los Angeles counties, extending from Morro Bay in the north to Malibu ...

, who mined the asphalt and used it as a sealant for waterproofing their

tomol A ''tomol'' or ''tomolo'' (Chumash) or ''te'aat'' or ''ti'at'' (Tongva/Kizh) are plank-built boats, historically and currently in the Santa Barbara and Los Angeles area. They replaced or supplemented tule reed boats. The boats were between in le ...

s (plank-built boats) and other purposes. The area was named "La Carpinteria" (the carpentry) by a Spanish expedition under explorer

Gaspar de Portolá Gaspar de Portolá y Rovira (January 1, 1716 – October 10, 1786) was a Spanish military officer, best known for leading the Portolá expedition into California and for serving as the first List of governors of California before 1850, Governor ...

, which arrived in the area on August 17, 1769. Starting around 1915, the tar pits were mined and the asphalt was used for building a coastal highway. In 1933, the area was designated a state beach and in 1941 it was formally opened to the public. The tar pits have trapped and preserved hundreds of Pleistocene Age birds and animals. Some findings are on display at the Carpinteria Valley Museum of History, but no paleontological studies have been conducted because the tar pits were used as a local rubbish dump.

References

{{Reflist Asphalt lakes Carpinteria, California Parks in Santa Barbara County, California Pleistocene paleontological sites of North America Lagerstätten Natural history of California Paleontology in California Oil fields in Santa Barbara County, California

Geography

Geology

History

See also

References