The Surat Basin is a geological basin in eastern Australia. It is part of the

Great Artesian Basin The Great Artesian Basin (GAB), located in Australia, is the largest and deepest artesian basin in the world, stretching over , with measured water temperatures ranging from . The basin provides the only source of fresh water through much of ...

drainage basin of

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. The Surat Basin extends across an area of 270,000 square kilometres and the southern third of the basin occupies a large part of northern

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

, the remainder is in

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

. It comprises

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

through to

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

aged

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand an ...

s derived from

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

and

Permian The Permian ( ) is a geologic period and 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 251.9 Mya. It is the last period of the Paleoz ...

arc rocks of the

Hunter-Bowen orogeny The Hunter-Bowen Orogeny was a significant arc accretion event in the Permian and Triassic periods affecting approximately 2,500 km of the Australian continental margin. The Hunter-Bowen Orogeny occurred in two main phases, a Permian accreti ...

. Towns situated above the basin, once dominated by agriculture, are experiencing a boom as mines and infrastructure in the area are expanded.

Formation

The Surat Basin is an intracratonic basin that covers a sizeable section of

and southern

. It was formed by

fluvial In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluviog ...

sedimentation of an intracratonic area which underwent sediment sag-loading in the Jurassic to Cretaceous.

Stratigraphy

The western central parts of the Surat Basin

unconformably An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval o ...

overlies the

Palaeozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and '' ...

igneous Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or ...

metamorphic Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causin ...

and

sedimentary rocks Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles t ...

of the

Lachlan Fold Belt The Lachlan Fold Belt (LFB) or Lachlan Orogen is a geological subdivision of the east part of Australia. It is a zone of folded and faulted rocks of similar age. It dominates New South Wales and Victoria (Australia), Victoria, also extending into T ...

In the east and northern parts of Queensland it unconformably overlies the sedimentary basin rocks of the Hunter-Bowen Orogen. The Surat Basin overlies parts of the

Bowen Basin The Bowen Basin contains the largest coal reserves in Australia. This major coal-producing region contains one of the world's largest deposits of bituminous coal. The Basin contains much of the known Permian coal resources in Queensland includ ...

in southern Queensland, and overlies the

Gunnedah Basin Gunnedah is a town in north-eastern New South Wales, Australia and is the seat of the Gunnedah Shire local government area. In the the town recorded a population of 9,726. Gunnedah is situated within the Liverpool Plains, a fertile agricultu ...

in central New South Wales. Palaeozoic basement highs mark the western and eastern boundaries of the Surat Basin. The Nebine Ridge delineates the boundary between the Surat Basin and the Eromanga Basin to the west. The Nebine Ridge is well developed in Queensland and gravity data indicate that the southern extension of the ridge into northern New South Wales is terminated by cross faulting. In Queensland the Kumbarilla Ridge divides the Surat Basin from the Clarence-Moreton Basin to the east. The mostly flat-lying basin has a maximum thickness of about 2,500 m in Queensland, with up to 1,800 m preserved in New South Wales. The basin hosts the fossiliferous early to middle Cenomanian

Griman Creek Formation The Griman Creek Formation is a geological formation in northern New South Wales and southern Queensland, Australia whose strata date back to the Albian-Cenomanian of the Early-Late Cretaceous.Bell et al., 2019 It is most notable being a major s ...

Economic geology

More than 100 hydrocarbon accumulations have been found in the basin however only half are producing. The Surat Basin is not very important a target for

oil An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) & lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturated ...

as the

source rock In petroleum geology, source rock is rock which has generated hydrocarbons or which could generate hydrocarbons. Source rocks are one of the necessary elements of a working petroleum system. They are organic-rich sediments that may have been depos ...

s have not generally been subjected to suitable conditions to evolve oil. There is some slight natural gas potential. Jurassic

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 elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when dea ...

seams have been worked and explored in the Queensland portions of the basin.

Mines

The basin has a number of mines such as Wilkie Creek Mine where Peabody Energy Australia mines and then exports coal.Queensland's World-class Coals: Mine Production and Developments
December 2005. Retrieved 19 April 2007.

Coal seam methane

The basin has a number of coal seam methane fields - also known as

coalbed methane Coalbed methane (CBM or coal-bed methane), coalbed gas, coal seam gas (CSG), or coal-mine methane (CMM) is a form of natural gas extracted from coal beds. In recent decades it has become an important source of energy in United States, Canada, Au ...

- developing in the region. These fields presently supply the domestic market, including a number of power stations and the Roma to Brisbane Pipeline. A number of gas companies have recently announced plans to develop liquified natural gas plants in or around

Gladstone William Ewart Gladstone ( ; 29 December 1809 – 19 May 1898) was a British statesman and Liberal politician. In a career lasting over 60 years, he served for 12 years as Prime Minister of the United Kingdom, spread over four non-conse ...

to export Surat Basin gas to international markets. The

Port of Gladstone The Port of Gladstone is Queensland's largest multi-commodity port and the fifth largest multi-commodity port in Australia. It is the world's fourth largest coal exporting terminal. It is within the locality of Callemondah in Gladstone in Centra ...

is undergoing a A$3.5 billion expansion to accommodate expected demands. In 2010, two energy companies confirmed their mines have the potential to affect groundwater levels.

References

{{coord, 30, 50, 36.93, S, 149, 30, 03.29, E, display=title, region:AU_type:city_source:GNS-enwiki Geology of Queensland Geology of New South Wales Sedimentary basins of Australia Coal mining regions in Australia Natural gas in Queensland Energy in New South Wales