HOME

TheInfoList



OR:

The Colorado Basin () is a
sedimentary basin Sedimentary basins are region-scale depressions of the Earth's crust where subsidence has occurred and a thick sequence of sediments have accumulated to form a large three-dimensional body of sedimentary rock They form when long-term subsidence ...
located in northeastern
Patagonia Patagonia () is a geographical region that includes parts of Argentina and Chile at the southern end of South America. The region includes the southern section of the Andes mountain chain with lakes, fjords, temperate rainforests, and glaciers ...
. The basin stretches across an area of approximately , of which onshore in the southern
Buenos Aires Province Buenos Aires, officially the Buenos Aires Province, is the largest and most populous Provinces of Argentina, Argentine province. It takes its name from the city of Buenos Aires, the capital of the country, which used to be part of the province an ...
and the easternmost
Río Negro Province Río Negro (, ''Black River'') is a province of Argentina, located in northern Patagonia. Neighboring provinces are from the south clockwise Chubut, Neuquén, Mendoza, La Pampa and Buenos Aires. To the east lies the Atlantic Ocean. Its cap ...
extending offshore in the
South Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...
. The basin comprises a sedimentary succession dating from the
Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...
(pre-rift stage) and
Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...
(rift stage) to the
Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...
, representing the
passive margin A passive margin is the transition between Lithosphere#Oceanic lithosphere, oceanic and Lithosphere#Continental lithosphere, continental lithosphere that is not an active plate continental margin, margin. A passive margin forms by sedimentatio ...
tectonic phase of the basin history. The Mesozoic rifting in the basin resulted from the break-up of
Pangea Pangaea or Pangea ( ) was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia (continent), Siberia during the Carboniferous period ...
and the formation of the South Atlantic. Long hiatuses exist in the succession. The basin is of paleontological significance for hosting fossiliferous stratigraphic units dating to the
Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...
. The
Arroyo Chasicó Formation Arroyo often refers to: * Arroyo (watercourse), an intermittently dry creek Arroyo may also refer to: Places United States * Arroyo, Pennsylvania * Arroyo, Puerto Rico, a municipality * Arroyo, West Virginia Spain * Arroyo (Santillana del Mar), ...
defines the
Chasicoan The Chasicoan ( or ) age is a period of geologic time from 10–9 Ma within the Late Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Mayoan and precedes the Huayquerian age.
South American land mammal age The South American land mammal ages (SALMA) establish a geologic timescale for prehistoric South American fauna beginning 64.5 Ma during the Paleocene and continuing through to the Late Pleistocene (0.011 Ma). These periods are referred to as age ...
and contains a rich mammal and other vertebrate fauna. The contemporaneous Cerro Azul Formation has provided fossil
rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...
s,
armadillo Armadillos () are New World placental mammals in the order (biology), order Cingulata. They form part of the superorder Xenarthra, along with the anteaters and sloths. 21 extant species of armadillo have been described, some of which are dis ...
s and
opossum Opossums () are members of the marsupial order Didelphimorphia () endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 126 species in 18 genera. Opossums originated in South America and entered North A ...
s. The Middle to Late Miocene Gran Bajo del Gualicho Formation contains vertebrate fossils of the
cetacea Cetacea (; , ) is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively c ...
n '' Preaulophyseter gualichensis''. The Río Negro Formation has provided fossils of the
glyptodont Glyptodonts are an extinct clade of large, heavily armoured armadillos, reaching up to in height, and maximum body masses of around 2 tonnes. They had short, deep skulls, a fused vertebral column, and a large bony carapace made up of hundreds o ...
'' Plohophorus figuratus''. The Permian succession in the basin has provided
flora Flora (: floras or florae) is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. The corresponding term for animals is ''fauna'', and for f ...
microfossil A microfossil is a fossil that is generally between 0.001 mm and 1 mm in size, the visual study of which requires the use of light or electron microscopy. A fossil which can be studied with the naked eye or low-powered magnification, ...
s. Contrasting with the South Atlantic passive margin basins to the north (
Santos Basin The Santos Basin () is an approximately large mostly offshore sedimentary basin. It is located in the south Atlantic Ocean, some southeast of Santos, São Paulo, Santos, Brazil. The basin is one of the Brazilian basins to have resulted from th ...
in southern Brazil) and south; Golfo San Jorge and Austral Basins, the Colorado Basin does not produce hydrocarbons. Exploration for petroleum started in the 1940 with the drilling of two onshore wells and several onshore and offshore wells have been drilled in the 1960s, 1970s and 1990s. The main
source rock In petroleum geology, source rock is a sedimentary rock which has generated hydrocarbons or which has the potential to generate hydrocarbons. Source rocks are one of the necessary elements of a working petroleum system. They are organic-rich sedim ...
s are found in the Permian succession, with reservoir rocks the Colorado Formation. Seals are provided by the
Early Paleocene The Danian is the oldest age (geology), age or lowest stage (stratigraphy), stage of the Paleocene Epoch or series (stratigraphy), Series, of the Paleogene Period or system (stratigraphy), System, and of the Cenozoic Era or Erathem. The beginnin ...
Pedro Luro Formation.


Description

The Colorado Basin stretches across an approximate area of with about onshore, underlying the southernmost
Buenos Aires Province Buenos Aires, officially the Buenos Aires Province, is the largest and most populous Provinces of Argentina, Argentine province. It takes its name from the city of Buenos Aires, the capital of the country, which used to be part of the province an ...
and the southeasternmost
Río Negro Province Río Negro (, ''Black River'') is a province of Argentina, located in northern Patagonia. Neighboring provinces are from the south clockwise Chubut, Neuquén, Mendoza, La Pampa and Buenos Aires. To the east lies the Atlantic Ocean. Its cap ...
. Cities inside the basin are
Bahía Blanca Bahía Blanca (; English: ''White Bay''), colloquially referred to by its own local inhabitants as simply Bahía, is a city in the Buenos Aires Province, Buenos Aires province of Argentina, centered on the northwestern end of the eponymous Blanc ...
and
Carmen de Patagones Carmen de Patagones is the southernmost city in the . Geography It is located 937 km southwest from the city of Buenos Aires, on the north bank of the Río Negro ("Black River"), near the Atlantic Ocean, and opposite Viedma, capital of ...
in Buenos Aires Province and Viedma in Río Negro Province, the earliest founded city in
Patagonia Patagonia () is a geographical region that includes parts of Argentina and Chile at the southern end of South America. The region includes the southern section of the Andes mountain chain with lakes, fjords, temperate rainforests, and glaciers ...
. The onshore part of the basin is crossed by the eponymous
Colorado Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...
and Río Negro rivers. Surrounding the Río Negro, many
salt lake A salt lake or saline lake is a landlocked body of water that has a concentration of salts (typically sodium chloride) and other dissolved minerals significantly higher than most lakes (often defined as at least three grams of salt per liter). I ...
s are present in the basin.Geologic Map Hojas 4163-II/IV & I/III, 2006 Some authors group the basin together with the Claromecó Basin to the north.Balarino, 2012, p.344 The offshore part of the Colorado Basin laterally correlates with and gradually ranges into the sub-parallel Salado Basin and the deeper offshore Argentina Basin.Pucci, 2006, p.17ENARSA, s.a., p.3 The offshore extension of the basin into neighboring basins led to different definitions of its area, some authors use a surface area of .ENARSA, s.a., p.2 The Colorado Basin is bound to the north by the Ventania High,Daners et al., 2016, p.285
Sierra de la Ventana Sierra de La Ventana is a village in Tornquist Partido in the southwest of the Province of Buenos Aires, Argentina. With a population of 1,819 inhabitants (), it is one of the most attractive tourist centres in the Province and has numerous recre ...
,Balarino, 2009, p.20 or Sierras Australes, separating the basin from the Claromecó Basin, and to the south by the Rawson,ENARSA, s.a., p.1 or Río Negro High. In the northwest, the basin grades into the Macachín Basin and the western boundary is formed by the San Rafael Block.Barredo & Stinco, 2010, p.60


Basin evolution

The basin started forming in the
Middle Middle or The Middle may refer to: * Centre (geometry), the point equally distant from the outer limits. Places * Middle (sheading), a subdivision of the Isle of Man * Middle Bay (disambiguation) * Middle Brook (disambiguation) * Middle Creek ...
to
Late Jurassic The Late Jurassic is the third Epoch (geology), epoch of the Jurassic Period, and it spans the geologic time scale, geologic time from 161.5 ± 1.0 to 143.1 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic stratum, strata.Owen ...
with the break-up of
Pangea Pangaea or Pangea ( ) was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia (continent), Siberia during the Carboniferous period ...
and the formation of the Southern Atlantic.Geologic Map Hojas 3963-III & IV, 2009, p.42 The main rifting took place in the
Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...
. The pre-rift sequence of the basin comprises the
Pennsylvanian Pennsylvanian may refer to: * A person or thing from Pennsylvania * Pennsylvanian (geology) The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, on the International Commission on Stratigraphy, ICS geologic timesc ...
Lolén Formation of the Ventana Group,Balarino, 2009, p.24 and the Sauce Grande, Piedra Azul, Bonete and Tunas Formations of the Pillahuincó Group, dating to the
Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...
.Balarino, 2009, p.22 During the late
Paleozoic The Paleozoic ( , , ; or Palaeozoic) Era is the first of three Era (geology), geological eras of the Phanerozoic Eon. Beginning 538.8 million years ago (Ma), it succeeds the Neoproterozoic (the last era of the Proterozoic Eon) and ends 251.9 Ma a ...
, the Colorado Basin was located in the south polar region, causing a sequence of
glacial A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...
deposits in the basin. These deposits were mostly sourced from the African basin, the
Karoo The Karoo ( ; from the Afrikaans borrowing of the South Khoekhoe Khoemana (also known as !Orakobab or Korana) word is a semidesert natural region of South Africa. No exact definition of what constitutes the Karoo is available, so its extent is ...
and
Kalahari Basin The Kalahari Basin, also known as the Kalahari Depression, Okavango Basin or the Makgadikgadi Basin, is an endorheic basin and large lowland area covering approximately — mostly within Botswana and Namibia, but also parts of Angola, South A ...
s. The Early Permian sediments are characterized by the presence of
diamictite Diamictite (; from Ancient Greek (): 'through' and (): 'mixed') is a type of lithified sedimentary rock that consists of nonsorted to poorly sorted terrigenous sediment containing particles that range in size from clay to boulders, suspended ...
s. A transgression in the Permian led to the deposition of the Piedra Azul Formation.Balarino, 2009, p.23 The succession contains several hiatuses, dating to the
Triassic The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...
and
Early Jurassic The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic� ...
,
Albian The Albian is both an age (geology), age of the geologic timescale and a stage (stratigraphy), stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early Cretaceous, Early/Lower Cretaceous epoch (geology), Epoch/s ...
and
Paleogene The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...
.ENARSA, s.a., p.4 The early
Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...
succession is missing, and the main rifting phase happened in the
Barremian The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 125.77 Ma (million years ago) and 121.4 ± 1.0 Ma (Historically, this stage was placed at 129.4 million to approximately 125 million years ago) It is a ...
and
Aptian The Aptian is an age (geology), age in the geologic timescale or a stage (stratigraphy), stage in the stratigraphic column. It is a subdivision of the Early Cretaceous, Early or Lower Cretaceous epoch (geology), Epoch or series (stratigraphy), S ...
, around 120 million years ago, represented in the Fortín Formation.Barredo & Stinco, 2010, p.52 The post-rift sag stage dates to the early
Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...
leading to the deposition of the
alluvial Alluvium (, ) 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. Alluvium is also sometimes called alluvial deposit. Alluvium is ...
and
fluvial A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it ru ...
sediments of the Colorado Formation. The drift stage is represented by the Pedro Luro Formation. The later Cenozoic succession is characteristic of a terrestrial
passive margin A passive margin is the transition between Lithosphere#Oceanic lithosphere, oceanic and Lithosphere#Continental lithosphere, continental lithosphere that is not an active plate continental margin, margin. A passive margin forms by sedimentatio ...
setting and comprises the
Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...
Elvira Elvira is a female given name. It is believed to have first been recorded in medieval Spain, while other sources claim that it is likely of Germanic ( Gothic) origin. In the Balkans, Elvira is popular among Bosniaks, Croats, and Slovenes in the ...
,
Middle Miocene The Middle Miocene is a sub-epoch of the Miocene epoch (geology), epoch made up of two Stage (stratigraphy), stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene. The sub-epoch lasted from 15.97 ± 0. ...
Barranca Final Formation,Geologic Map Hojas 3963-III & IV, 2009, p.39 and the Middle to Late Miocene Gran Bajo de Gualicho Formation.Reichler, 2010, p.192 This formation in most of the basin is overlain by the Río Negro Formation.Reichler, 2010, p.183 The Late Miocene succession in the westernmost area of the basin is represented by the
Arroyo Chasicó Arroyo often refers to: * Arroyo (watercourse), an intermittently dry creek Arroyo may also refer to: Places United States * Arroyo, Pennsylvania * Arroyo, Puerto Rico, a municipality * Arroyo, West Virginia Spain * Arroyo (Santillana del Mar), ...
and eolian Cerro Azul Formations,Visconti et al., 2010, p.259 cropping out in the northern onshore part of the basin.Geologic Map Hojas 3963-III & IV, 2009, p.5 This sequence is covered by the
Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...
to
Early Pliocene Early may refer to: Places in the United States * Early, Iowa, a city * Early, Texas, a city * Early Branch, a stream in Missouri * Early County, Georgia * Fort Early, Georgia, an early 19th century fort Music * Early B, stage name of Jamaican d ...
eolian and
fluvial A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it ru ...
Río Negro Formation,Pérez, 2010, p.7Geologic Map Hojas 3963-III & IV, 2009, p.8 outcropping in a thin band along the eponymous river.


Stratigraphy


Paleontological significance

The Miocene formations cropping out onshore have provided a rich
mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...
fauna. The
Arroyo Chasicó Formation Arroyo often refers to: * Arroyo (watercourse), an intermittently dry creek Arroyo may also refer to: Places United States * Arroyo, Pennsylvania * Arroyo, Puerto Rico, a municipality * Arroyo, West Virginia Spain * Arroyo (Santillana del Mar), ...
is the defining formation for the
Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...
Chasicoan The Chasicoan ( or ) age is a period of geologic time from 10–9 Ma within the Late Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Mayoan and precedes the Huayquerian age.
South American land mammal age The South American land mammal ages (SALMA) establish a geologic timescale for prehistoric South American fauna beginning 64.5 Ma during the Paleocene and continuing through to the Late Pleistocene (0.011 Ma). These periods are referred to as age ...
, ranging from 10 to 9 million years ago.Chasicoan
at
Fossilworks Fossilworks was a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cr ...
.org
The formation contains many mammal species, birds and reptiles.Arroyo Chasicó
at
Fossilworks Fossilworks was a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cr ...
.org
The Cerro Azul Formation contains fossils of the
rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...
s '' Chasichimys bonaerense'',Verzi et al., 2008 '' Neocavia pampeana'',Madozzo Jaén et al., 2018, p.250 '' Reigechimys plesiodon'' and ''R. simplex'',Sostillo et al., 2014 the
armadillo Armadillos () are New World placental mammals in the order (biology), order Cingulata. They form part of the superorder Xenarthra, along with the anteaters and sloths. 21 extant species of armadillo have been described, some of which are dis ...
s '' Chasicotatus ameghinoi'', and '' Macrochorobates scalabrinii'', and the
opossum Opossums () are members of the marsupial order Didelphimorphia () endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 126 species in 18 genera. Opossums originated in South America and entered North A ...
'' Zygolestes tatei'',Goin et al., 2000, p.108 among other mammals. The Río Negro Formation has provided fossils of the
glyptodont Glyptodonts are an extinct clade of large, heavily armoured armadillos, reaching up to in height, and maximum body masses of around 2 tonnes. They had short, deep skulls, a fused vertebral column, and a large bony carapace made up of hundreds o ...
'' Plohophorus figuratus''.Punta Bermeja
at
Fossilworks Fossilworks was a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cr ...
.org
The marine Gran Bajo de Gualicho Formation contains many
bivalve Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...
,
gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...
and
echinoid Sea urchins or urchins () are echinoderms in the class Echinoidea. About 950 species live on the seabed, inhabiting all oceans and depth zones from the intertidal zone to deep seas of . They typically have a globular body covered by a spiny p ...
fossils,Reichler, 2010, pp.191-192 and the
cetacea Cetacea (; , ) is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively c ...
n '' Preaulophyseter gualichensis''.Buono, 2013, p.36 The Eocene succession in boreholes of the basin has provided many species of
dinoflagellate The Dinoflagellates (), also called Dinophytes, are a monophyletic group of single-celled eukaryotes constituting the phylum Dinoflagellata and are usually considered protists. Dinoflagellates are mostly marine plankton, but they are also commo ...
s,Daners et al., 2016, p.293 and in the Permian sequence 131 species of spores, algae, funghi and
pollen Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced Gametophyte#Heterospory, microgametophytes), which produce male gametes (sperm ...
were registered.Balarino, 2012, p.343


Petroleum exploration

Contrary to other Southern Atlantic marginal basins, as the Golfo San Jorge and Austral Basins to the south, and
Santos Basin The Santos Basin () is an approximately large mostly offshore sedimentary basin. It is located in the south Atlantic Ocean, some southeast of Santos, São Paulo, Santos, Brazil. The basin is one of the Brazilian basins to have resulted from th ...
of Brazil to the north, the Colorado Basin is not producing hydrocarbons. The first wells in the northern onshore part of the basin were drilled in 1946 (Pedro Luro-1) and 1948 (Ombucta-1) by
YPF YPF S.A. (, formerly ; English: "Fiscal Oilfields") is a vertically integrated, majority state-owned Argentine energy company, engaged in oil and gas exploration and production, and the transportation, refining, and marketing of gas and pe ...
. Another phase of onshore exploration happened in the 1960s, with seven wells drilled by
Shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses Science Biology * Seashell, a hard outer layer of a marine ani ...
.Rossello, 2016, p.175 Offshore drilling started in 1970 by
Hunt Oil Hunt Oil Co. is an independent oil and gas company headquartered in Dallas, Texas. It conducts its main oil production activities in the United States, Canada and, as of 1984, in Yemen. In the past, the company was owned by American oil tycoon ...
and after seismic acquisition in the 1970s by YPF,ENARSA, s.a., p.8 some wells were drilled in 1977 by the same company. Renewed exploration started in the mid-1990s with several wells drilled by Union Texas and Shell.ENARSA, s.a., p.5 The offshore Cruz del Sur x-1 well provided oil shows of 39°
API An application programming interface (API) is a connection between computers or between computer programs. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how to build ...
.Pucci, 2006, p.18


See also

*
Pelotas Basin The Pelotas Basin (, ) is a mostly offshore sedimentary basin of approximately in the South Atlantic, administratively part of the southern states Santa Catarina and Rio Grande do Sul of Brazil and the departments Cerro Largo, Rocha and Treinta ...
*
Cañadón Asfalto Basin The Cañadón Asfalto Basin () is an irregularly shaped sedimentary basin located in north-central Patagonia, Argentina. The basin stretches from and partly covers the North Patagonian Massif in the north, a high forming the boundary of the basin ...
*
Golfo San Jorge Basin 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 i ...
* Austral Basin


References


Bibliography

;General * * * * * * * ;Geologic maps * * ;Arroyo Chasicó Formation * * * * ;Cerro Azul Formation * * * * * * ;Gran Bajo del Gualicho Formation * * ;Río Negro Formation * {{Sedimentary basins of Argentina Rift basins Passive margins Mesozoic rifts and grabens Sedimentary basins of Argentina Geology of Buenos Aires Province Geology of Río Negro Province Geology of Patagonia Geology of the Atlantic Ocean