In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics.
The Maracaibo Basin, also known as Lake Maracaibo natural region, Lake Maracaibo depression or Lake Maracaibo Lowlands, is a foreland basin and one of the eight natural regions of Venezuela, found in the northwestern corner of Venezuela in South America. Covering over 36,657 square km, it is a hydrocarbon-rich region that has produced over 30 billion bbl of oil with an estimated 44 billion bbl yet to be recovered. The basin is characterized by a large shallow tidal estuary, Lake Maracaibo, located near its center. The Maracaibo basin has a complex tectonic history that dates back to the Jurassic period with multiple evolution stages. Despite its complexity, these major tectonic stages are well preserved within its stratigraphy. This makes The Maracaibo basin one of the most valuable basins for reconstructing South America's early tectonic history.
Hollis Dow Hedberg was an American geologist specializing in petroleum exploration. His contribution to stratigraphic classification of rocks and procedures is a monumental work which received universal acceptance. The firm he worked for, the Gulf Oil Corporation in Venezuela, trusted his findings and explored what had until then been uncharted territory. As a result, they reaped huge benefits from their petroleum findings. Hedberg taught at Princeton University from 1959 until his retirement in 1971. He was awarded the Mary Clark Thompson Medal by the National Academy of Sciences in 1973. In 1975 he was awarded the Wollaston Medal by the Geological Society of London. Hedberg won the Sidney Powers Memorial Award in 1963.
The Magallanes Basin or Austral Basin is a major sedimentary basin in southern Patagonia. The basin covers a surface of about 170,000 to 200,000 square kilometres and has a NNW-SSE oriented shape. The basin is bounded to the west by the Andes mountains and is separated from the Malvinas Basin to the east by the Río Chico-Dungeness High. The basin evolved from being an extensional back-arc basin in the Mesozoic to being a compressional foreland basin in the Cenozoic. Rocks within the basin are Jurassic in age and include the Cerro Toro Formation. Three ages of the SALMA classification are defined in the basin; the Early Miocene Santacrucian from the Santa Cruz Formation and Friasian from the Río Frías Formation and the Pleistocene Ensenadan from the La Ensenada Formation.
In geology, a basin is a region where subsidence generates accommodation space for the deposition of sediments. A pull-apart basin is a structural basin where two overlapping faults or a fault bend creates an area of crustal extension undergoing tension, which causes the basin to sink down. Frequently, the basins are rhombic or sigmoidal in shape. Dimensionally, basins are limited to the distance between the faults and the length of overlap. Pull-apart basins are also referred to as overlapping-tension-zones (OTZ).
The Paraná Basin is a large cratonic sedimentary basin situated in the central-eastern part of South America. About 75% of its areal distribution occurs in Brazil, from Mato Grosso to Rio Grande do Sul states. The remainder area is distributed in eastern Paraguay, northeastern Argentina and northern Uruguay. The shape of the depression is roughly elliptical and covers an area of about 1,500,000 km2 (580,000 sq mi).
The Exshaw Formation is a stratigraphic unit in the Western Canada Sedimentary Basin. It takes the name from the hamlet of Exshaw, Alberta in the Canadian Rockies, and was first described from outcrops on the banks of Jura Creek north of Exshaw by P.S. Warren in 1937. The formation is of Late Devonian to Early Mississippian age as determined by conodont biostratigraphy, and it straddles the Devonian-Carboniferous boundary.
Neuquén Basin is a sedimentary basin covering most of Neuquén Province in Argentina. The basin originated in the Jurassic and developed through alternating continental and marine conditions well into the Tertiary. The basin bounds to the west with the Andean Volcanic Belt, to the southeast with the North Patagonian Massif and to the northeast with the San Rafael Block and to the east with the Sierra Pintada System. The basin covers an area of approximately 120,000 square kilometres (46,000 sq mi). One age of the SALMA classification, the Colloncuran, is defined in the basin, based on the Collón Curá Formation, named after the Collón Curá River, a tributary of the Limay River.
The Beaverhill Lake Group is a geologic unit of Middle Devonian to Late Devonian age in the Western Canada Sedimentary Basin that is present in the southwestern Northwest Territories, northeastern British Columbia and Alberta. It was named by the geological staff of Imperial Oil in 1950 for Beaverhill Lake, Alberta, based on the core from a well that they had drilled southeast of the lake, near Ryley, Alberta.
The Elk Point Group is a stratigraphic unit of Early to Middle Devonian age in the Western Canada and Williston sedimentary basins. It underlies large area that extends from southern boundary of the Northwest Territories in Canada to North Dakota in the United States. It has been subdivided into numerous formations, many which host major petroleum and natural gas reservoirs.
The Middle Magdalena Valley, Middle Magdalena Basin or Middle Magdalena Valley Basin is an intermontane basin, located in north-central Colombia between the Central and Eastern Ranges of the Andes. The basin, covering an area of 34,000 square kilometres (13,000 sq mi), is situated in the departments of Santander, Boyacá, Cundinamarca and Tolima.
The Angola Basin is located along the West African South Atlantic Margin which extends from Cameroon to Angola. It is characterized as a passive margin that began spreading in the south and then continued upwards throughout the basin. This basin formed during the initial breakup of the supercontinent Pangaea during the early Cretaceous, creating the Atlantic Ocean and causing the formation of the Angola, Cape, and Argentine basins. It is often separated into two units: the Lower Congo Basin, which lies in the northern region and the Kwanza Basin which is in the southern part of the Angola margin. The Angola Basin is famous for its "Aptian Salt Basins," a thick layer of evaporites that has influenced topography of the basin since its deposition and acts as an important petroleum reservoir.
The Andean foreland basins or Sub-Andean basins are a group of foreland basins located in the western half of South America immediately east of the Andes mountains. The Andean foreland basins in the Amazon River's catchment area are known as the Amazonian foreland basins.
The Golfo San Jorge Basin is a hydrocarbon-rich sedimentary basin located in eastern Patagonia, Argentina. The basin covers the entire San Jorge Gulf and an inland area west of it, having one half located in Santa Cruz Province and the other in Chubut Province. The northern boundary of the basin is the North Patagonian Massif while the Deseado Massif forms the southern boundary of the basin. The basin has largely developed under condition of extensional tectonics, including rifting.
Cuyo Basin is a sedimentary basin in Mendoza Province, western Argentina. The Cuyo Basin has a NNW-SSE elongated shape and is limited to the west by the Sierra Pintada System and to the east by the Pampean pericraton. To the north the basin reaches the area around the city of Mendoza.
The Cesar-Ranchería Basin is a sedimentary basin in northeastern Colombia. It is located in the southern part of the department of La Guajira and northeastern portion of Cesar. The basin is bound by the Oca Fault in the northeast and the Bucaramanga-Santa Marta Fault in the west. The mountain ranges Sierra Nevada de Santa Marta and the Serranía del Perijá enclose the narrow triangular intermontane basin, that covers an area of 11,668 square kilometres (4,505 sq mi). The Cesar and Ranchería Rivers flow through the basin, bearing their names.
The Cocinetas Basin is a small sedimentary basin of approximately 1,000 square kilometres (390 sq mi) in northeasternmost Colombia. The onshore pull-apart basin is located in the department of La Guajira at the border with Zulia, Venezuela. The basin is bound by three sets of hills; the Serranía de Jarara, Serranía Macuira and Serranía Cocinas, with the eastern boundary formed by the Gulf of Venezuela, part of the Caribbean Sea.
The Jimol Formation is a fossiliferous geological formation of the Cocinetas Basin in the northernmost department of La Guajira. The formation consists of calcareous lithic and fossiliferous sandstones, siltstones and mudstones. The Jimol Formation dates to the Neogene period; Burdigalian stage, Santacrucian in the SALMA classification, and has a maximum thickness of 203 metres (666 ft).
The Castilletes Formation is a fossiliferous geological formation of the Cocinetas Basin in the northernmost department of La Guajira, Colombia. The formation consists of fossiliferous mudstones, siltstones and medium-grained to conglomeratic fossiliferous lithic to quartzitic sandstones. The Castilletes Formation dates to the Neogene period; Burdigalian to Langhian stages, Colloncuran and Friasian in the SALMA classification, and has a maximum thickness of 440 metres (1,440 ft).
The Ware Formation is a fossiliferous geological formation of the Cocinetas Basin in the northernmost department of La Guajira. The formation consists of fine lithic to quartzitic sandstones, mudstones, pebbly conglomerates with sedimentary and metamorphic rock fragments, fossiliferous packstones and sandy to conglomeratic beds with high fossil content. The Ware Formation dates to the Neogene and Quaternary periods; Late Miocene to Early Pleistocene epochs, typically Pliocene, Uquian, Chapadmalalan and Montehermosan in the SALMA classification, and has a maximum thickness of 25 metres (82 ft).
