Pitch Lake
Encyclopedia
Asphalt
Asphalt or , also known as bitumen, is a sticky, black and highly viscous liquid or semi-solid that is present in most crude petroleums and in some natural deposits, it is a substance classed as a pitch...
in the world, located at La Brea in southwest Trinidad
Trinidad and Tobago
Trinidad and Tobago officially the Republic of Trinidad and Tobago is an archipelagic state in the southern Caribbean, lying just off the coast of northeastern Venezuela and south of Grenada in the Lesser Antilles...
, within the Siparia Regional Corporation
Siparia Regional Corporation
Siparia Regional Corporation is the Regional Corporation which handles local government functions in a 510.48 km² are of southwest Trinidad. It is one of 15 local government bodies in Trinidad and Tobago. The Siparia Regional Corporation is headquartered in Siparia...
. The lake covers about 40 ha
Hectare
The hectare is a metric unit of area defined as 10,000 square metres , and primarily used in the measurement of land. In 1795, when the metric system was introduced, the are was defined as being 100 square metres and the hectare was thus 100 ares or 1/100 km2...
and is reported to be 75 m deep.
Pitch Lake is a tourist attraction
Tourist attraction
A tourist attraction is a place of interest where tourists visit, typically for its inherent or exhibited cultural value, historical significance, natural or built beauty, or amusement opportunities....
that attracts about 20,000 visitors annually. It is also mined for asphalt by Lake Asphalt of Trinidad and Tobago
Lake Asphalt of Trinidad and Tobago
Lake Asphalt of Trinidad and Tobago is a company based in La Brea in Trinidad involved in the mining, processing and exporting of asphalt products from the Pitch Lake.-History:...
.
History
Pitch Lake has fascinated explorers and scientists, as well as attracting tourists, since its discovery by Sir Walter RaleighWalter Raleigh
Sir Walter Raleigh was an English aristocrat, writer, poet, soldier, courtier, spy, and explorer. He is also well known for popularising tobacco in England....
in 1595. Raleigh himself found immediate use for the asphalt to caulk his ship. Exported asphalt from Pitch Lake was also used to pave the streets of some regions of New York City.
Since its re-discovery, there have been numerous research investigations into the use and chemical composition of this material. Above all, there have been countless theories, postulations, and conclusions as to the size, source, and origin of the asphalt.
Geology
The origin of Pitch Lake is related to deep faultsGeologic fault
In geology, a fault is a planar fracture or discontinuity in a volume of rock, across which there has been significant displacement along the fractures as a result of earth movement. Large faults within the Earth's crust result from the action of tectonic forces...
in connection with subduction
Subduction
In geology, subduction is the process that takes place at convergent boundaries by which one tectonic plate moves under another tectonic plate, sinking into the Earth's mantle, as the plates converge. These 3D regions of mantle downwellings are known as "Subduction Zones"...
under the Caribbean Plate
Caribbean Plate
The Caribbean Plate is a mostly oceanic tectonic plate underlying Central America and the Caribbean Sea off the north coast of South America....
related to Barbados Arc. The lake has not been studied extensively, but it is believed that the lake is at the intersection of two faults, which allows oil from a deep deposit to be forced up. The lighter elements in the oil evaporated, leaving behind the heavier asphalt. Bacterial action on the asphalt at low pressures creates petroleum in asphalt.
Microbial life exists in the lake. The researchers indicated that extremophile
Extremophile
An extremophile is an organism that thrives in physically or geochemically extreme conditions that are detrimental to most life on Earth. In contrast, organisms that live in more moderate environments may be termed mesophiles or neutrophiles...
s inhabited the asphalt lake in populations ranging between 106 to 107 cells/gram.
Pitch Lake is one of several natural asphalt lakes
Tar pit
A tar pit, or more accurately known as an asphalt pit or asphalt lake, is a geological occurrence where subterranean bitumen leaks to the surface, creating a large area of natural asphalt.-Known tar pits:...
in the world. The La Brea Tar Pits
La Brea Tar Pits
The La Brea Tar Pits are a cluster of tar pits around which Hancock Park was formed, in the urban heart of Los Angeles. Asphaltum or tar has seeped up from the ground in this area for tens of thousands of years. The tar is often covered with water...
(Los Angeles
Los Ángeles
Los Ángeles is the capital of the province of Biobío, in the commune of the same name, in Region VIII , in the center-south of Chile. It is located between the Laja and Biobío rivers. The population is 123,445 inhabitants...
), McKittrick Tar Pits
McKittrick Tar Pits
The McKittrick Tar 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 state...
(McKittrick
McKittrick, California
McKittrick is a census-designated place in Kern County, California, United States. McKittrick is located northwest of Taft, at an elevation of 1056 feet . The population was 115 at the 2010 census, down from 160 at the 2000 census.-Geography:...
) and Carpinteria Tar Pits
Carpinteria Tar Pits
The Carpinteria Tar Pits are a series of natural asphalt lakes situated in the southern part of Santa Barbara County in southern California....
(Carpinteria
Carpinteria, California
Carpinteria is a small oceanside city located in southeastern Santa Barbara County, California, east of Santa Barbara and northwest of Ventura. The population was 13,040 at the 2010 census, down from 14,194 at the 2000 census....
) are all in the US
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
state of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. Lake Guanoco is in the Republic of Venezuela.
External links
- Trinidad's Pitch Lake, a pictorial by Richard Seaman.
- sciencenews.org article on life in the lake