The Eromanga Basin is a large

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 ...

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 ...

in central and northern

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. It covers parts of

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

, the

Northern Territory The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

, and

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

, and is a major component of the Great Artesian Basin. The Eromanga Basin covers 1,000,000 km² and overlaps part of the

Cooper Basin The Cooper Basin is a Permian-Triassic sedimentary geological basin in Australia. The intracratonic rift basin is located mainly in the southwestern part of Queensland and extends into northeastern South Australia. It is named after the Coop ...

. The basin is made of

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility. Although its permeabil ...

mudstone Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Mudstone is distinguished from ''shale'' by its lack of fissility.Blatt, H., and R.J. Tracy, 1996, ''Petrology.'' New York, New York, ...

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal i ...

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...

, and

red beds Red beds (or redbeds) are sedimentary rocks, typically consisting of sandstone, siltstone, and shale, that are predominantly red in color due to the presence of ferric oxides. Frequently, these red-colored sedimentary strata locally contain t ...

. Two impact structures have been identified in the basin, Mount Toondina crater and Tookoonooka crater. In Queensland and South Australia the Eromanga Basin has been explored and developed for petroleum production. Commercial quantities of gas were first discovered in 1976 and oil in 1978. The basin contains Australia's largest onshore oilfield, the Jackson oil field. Moomba is the centre of South Australia's oil production in the basin. The geology of the portion of the Eromanga Basin in New South Wales remains under-explored. During the middle of the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

period much of inland Australia was flooded by the Eromanga Sea, which shares its name with the contemporary Basin. Various fossil sites spanning the region record a diversity of marine life, including

Plesiosaurs The Plesiosauria or plesiosaurs are an Order (biology), order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared in the latest Triassic Period (geology), Period, possibly in the Rhaetian st ...

and

Ichthyosaurs Ichthyosauria is an taxonomy (biology), order of large extinction, extinct marine reptiles sometimes referred to as "ichthyosaurs", although the term is also used for wider clades in which the order resides. Ichthyosaurians thrived during much of ...

, that were abundant in the Eromanga Sea during the

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 ...

and

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 ...

ages.

References

External links

Eromanga Basin geology, Northern Territory Geological Survey
(accessed 2010-05-04)
Great Artesian Basin Factsheet, Queensland Department of Natural Resources and Water
(accessed 2007-10-27) {{Authority control

Basins Basin may refer to: Geography and geology * Depression (geology) ** Back-arc basin, a submarine feature associated with island arcs and subduction zones ** Debris basin, designed to prevent damage from debris flow ** Drainage basin (hydrology), ...

Sedimentary basins of Australia Natural gas fields in Australia Energy in South Australia Energy in Queensland Energy in New South Wales Energy in the Northern Territory

See also

References

External links