The South Lokichar Basin is a Cenozoic sedimentary basin in Kenya. It is part of the East African Rift system, although it is no longer active. Since 2012 it has been the location of a series of oil discoveries by Tullow Oil and its partners. [1]
The South Lokichar Basin is a north-south trending half-graben with the main bounding fault on its western margin. It is approximately 80 km long, 25 km wide and has a maximum depth of over 7 km. [2] The main fault, known as the Lokichar Fault, is relatively low angle and planar in section, although the dip varies considerably along strike from 12° to 60°. [3]
The basin is filled by a sequence of Oligocene (possibly as old as Eocene) to Miocene sedimentary rocks. There is one major interval of volcanic rocks near the top of the sequence called the Auwerwer basalts, dated using K–Ar dating as middle to late Miocene in age (12.5–10.7 Ma). [2]
Exploration in the basin began with the Loperot-1 well drilled by Royal Dutch Shell in 1992. This found some oil in thin sands, but proved the presence of a good quality and mature source rock and good quality reservoir sands. This phase of exploration ended as the company assessed the results as non-commercial. In 2008 Africa Oil Corp acquired a PSA for license 10BB over the basin. [4] In 2010 they farmed out part of their interest to Tullow, who became the operator. In 2012 drilling began with Ngamia-1, which was a major discovery. Subsequently, another eight discoveries have been made, all, like Ngamia, close to the basin bounding fault. There are now sufficient discovered resources for a commercial development. [1] The proposed export route for the oil is the Kenya Crude Oil Pipeline. [5]
The geology of the Appalachians dates back to more than 480 million years ago. A look at rocks exposed in today's Appalachian Mountains reveals elongate belts of folded and thrust faulted marine sedimentary rocks, volcanic rocks and slivers of ancient ocean floor – strong evidence that these rocks were deformed during plate collision. The birth of the Appalachian ranges marks the first of several mountain building plate collisions that culminated in the construction of the supercontinent Pangaea with the Appalachians and neighboring Little Atlas near the center. These mountain ranges likely once reached elevations similar to those of the Alps and the Rocky Mountains before they were eroded.
In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics.
The Los Angeles Basin is a sedimentary basin located in southern California, in a region known as the Peninsular Ranges. The basin is also connected to an anomalous group of east-west trending chains of mountains collectively known as the California Transverse Ranges. The present basin is a coastal lowland area, whose floor is marked by elongate low ridges and groups of hills that is located on the edge of the Pacific Plate. The Los Angeles Basin, along with the Santa Barbara Channel, the Ventura Basin, the San Fernando Valley, and the San Gabriel Basin, lies within the greater southern California region. On the north, northeast, and east, the lowland basin is bound by the Santa Monica Mountains and Puente, Elysian, and Repetto hills. To the southeast, the basin is bordered by the Santa Ana mountains and the San Joaquin Hills. The western boundary of the basin is marked by the Continental Borderland and is part of the onshore portion. The California borderland is characterized by northwest trending offshore ridges and basins. The Los Angeles Basin is notable for its great structural relief and complexity in relation to its geologic youth and small size for its prolific oil production. Yerkes et al. identify five major stages of the basin's evolution, which began in the Upper Cretaceous and ended in the Pleistocene. This basin can be classified as an irregular pull-apart basin accompanied by rotational tectonics during the post-early Miocene.
The Queen Charlotte Basin is a structural basin mostly beneath the continental shelf offshore, between the Queen Charlotte Islands, Vancouver Island, and the British Columbia mainland, roughly coincident with the physiographic region named the Hecate Depression.
The Gulf of Suez Rift is a continental rift zone that was active between the Late Oligocene and the end of the Miocene. It represented a continuation of the Red Sea Rift until break-up occurred in the middle Miocene, with most of the displacement on the newly developed Red Sea spreading centre being accommodated by the Dead Sea Transform. During its brief post-rift history, the deepest part of the remnant rift topography has been filled by the sea, creating the Gulf of Suez.
Lokichar is a settlement in Kenya's Turkana County.
The greater Turkana Basin in East Africa determines a large endorheic basin, a drainage basin with no outflow centered around the north-southwards directed Gregory Rift system in Kenya and southern Ethiopia. The deepest point of the basin is the endorheic Lake Turkana, a brackish Soda lake with a very high ecological productivity in the Gregory Rift.
The Columbus Basin is a foreland basin located off the south eastern coast of Trinidad within the East Venezuela Basin (EVB). Due to the intensive deformation occurring along the Caribbean and South American plates in this region, the basin has a unique structural and stratigraphic relationship. The Columbus Basin has been a prime area for hydrocarbon exploration and production as its structures, sediments and burial history provide ideal conditions for generation and storage of hydrocarbon reserves. The Columbus Basin serves as a depocenter for the Orinoco River delta, where it is infilled with 15 km of fluvio-deltaic sediment. The area has also been extensively deformed by series of north west to southeast normal faults and northeast to southwest trending anticline structures.
The offshore Indus Basin is one of the two basins in offshore Pakistan, the other one being the offshore Makran Basin. The Murray Ridge separates the two basins. The offshore Indus basin is approximately 120 to 140 kilometers wide and has an areal extent of ~20,000 square km.
The Taranaki Basin is an onshore-offshore Cretaceous rift basin on the West Coast of New Zealand. Development of rifting was the result of extensional stresses during the breakup of Gondwanaland. The basin later underwent fore-arc and intra-arc basin development, due to the subduction of the Pacific Plate under the Australian Plate at the Hikurangi Subduction System. The basin covers approximately 100,000 km2 of which the majority is offshore. The basin contains mostly marine sediment, with significant terrestrial sediment from the Late Cretaceous to the Eocene. The majority of New Zealand's oil and gas production occurs within the basin, with over 400 wells and approximately 20 oil and gas fields being drilled.
The Kutai sedimentary basin extends from the central highlands of Borneo, across the eastern coast of the island and into the Makassar Strait. With an area of 60,000 km2, and depths up to 15 km, the Kutai is the largest and deepest Tertiary age basin in Indonesia. Plate tectonic evolution in the Indonesian region of SE Asia has produced a diverse array of basins in the Cenozoic. The Kutai is an extensional basin in a general foreland setting. Its geologic evolution begins in the mid Eocene and involves phases of extension and rifting, thermal sag, and isostatic subsidence. Rapid, high volume, sedimentation related to uplift and inversion began in the Early Miocene. The different stages of Kutai basin evolution can be roughly correlated to regional and local tectonic events. It is also likely that regional climate, namely the onset of the equatorial ever wet monsoon in early Miocene, has affected the geologic evolution of Borneo and the Kutai basin through the present day. Basin fill is ongoing in the lower Kutai basin, as the modern Mahakam River delta progrades east across the continental shelf of Borneo.
Carabobo is an oil field located in Venezuela's Orinoco Belt. As one of the world's largest accumulations of recoverable oil, the recent discoveries in the Orinoco Belt have led to Venezuela holding the world's largest recoverable reserves in the world, surpassing Saudi Arabia in July 2010. The Carabobo oil field is majority owned by Venezuela's national oil company, Petroleos de Venezuela SA (PDVSA). Owning the majority of the Orinoco Belt, and its estimated 1.18 trillion barrels of oil in place, PDVSA is now the fourth largest oil company in the world. The field is well known for its extra Heavy crude oils, having an average specific gravity between 4 and 16 °API. The Orinoco Belt holds 90% of the world's extra heavy crude oils, estimated at 256 billion recoverable barrels. While production is in its early development, the Carabobo field is expected to produce 400,000 barrels of oil per day.
The Tarfaya Basin is a structural basin located in southern Morocco that extends westward into the Moroccan territorial waters in the Atlantic Ocean. The basin is named for the city of Tarfaya located near the border of Western Sahara, a region governed by the Kingdom of Morocco. The Canary Islands form the western edge of the basin and lie approximately 100 km to the west.
The Delta Field is located offshore from Nigeria on Oil Mining Leases (OML) 49 and 95. This is located within the Niger Delta Basin and sits in 12 feet of water. In 1965, the Delta 1 well was completed and the Delta Field opened in 1968 for production.
The Nam Con Son Basin formed as a rift basin during the Oligocene period. This basin is the southernmost sedimentary basin offshore of Vietnam, located within coordinates of 6°6'-9°45'N and 106°0-109°30'E in the East Vietnam Sea. It is the largest oil and gas bearing basin in Vietnam and has a number of producing fields.
The geology of Lebanon remains poorly studied prior to the Jurassic. The country is heavily dominated by limestone, sandstone, other sedimentary rocks, and basalt, defined by its tectonic history. In Lebanon, 70% of exposed rocks are limestone karst.
The geology of Ivory Coast is almost entirely extremely ancient metamorphic and igneous crystalline basement rock between 2.1 and more than 3.5 billion years old, comprising part of the stable continental crust of the West African Craton. Near the surface, these ancient rocks have weathered into sediments and soils 20 to 45 meters thick on average, which holds much of Ivory Coast's groundwater. More recent sedimentary rocks are found along the coast. The country has extensive mineral resources such as gold, diamonds, nickel and bauxite as well as offshore oil and gas.
The geology of Somaliland is very closely related to the geology of Somalia. Somaliland is a de facto independent country within the boundaries that the international community recognizes as Somalia. Because it encompasses the former territory of British Somaliland, the region is historically better researched than former Italian Somaliland. Somaliland is built on more than 700 million year old igneous and metamorphic crystalline basement rock.. These ancient units are covered in thick layers of sedimentary rock formed in the last 200 million years and influenced by the rifting apart of the Somali Plate and the Arabian Plate.
The geology of Senegal formed beginning more than two billion years ago. The Archean greenschist Birimian rocks common throughout West Africa are the oldest in the country, intruded by Proterozoic granites. Basins formed in the interior during the Paleozoic and filled with sedimentary rocks, including tillite from a glaciation. With the rifting apart of the supercontinent Pangaea in the Mesozoic, the large Senegal Basin filled with thick sequences of marine and terrestrial sediments. Sea levels declined in the Eocene forming large phosphate deposits. Senegal is blanketed in thick layers of terrestrial sediments formed in the Quaternary. The country has extensive natural resources, including gold, diamonds, and iron.
Kapuni is an onshore natural gas-condensate field located in the Taranaki Basin, a ~100,000 km2 partially-inverted rift basin on the Taranaki Peninsula in the North Island, New Zealand. Discovered in 1959 and brought into production in 1970, Kapuni remained New Zealand's only producing gas-condensate field until the offshore Maui gas field began production in 1979.