{{Use dmy dates|date=February 2018}} {{Use Australian English|date=February 2018}} The '''Surat Basin''' is a geological basin in eastern Australia. It is part of the [[Great Artesian Basin]] [[drainage basin]] of [[Australia]]. 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]], the remainder is in [[Queensland]]. It comprises [[Jurassic]] through to [[Cretaceous]] aged [[sediment]]s derived from [[Triassic]] and [[Permian]] arc rocks of the [[Hunter-Bowen orogeny]]. Towns situated above the basin, once dominated by agriculture, are experiencing a boom as mines and infrastructure in the area are expanded.<ref name="sbnbe"/>
==Formation== The Surat Basin is an intracratonic basin that covers a sizeable section of [[New South Wales]] and southern [[Queensland]]. It was formed by [[fluvial]] sedimentation of an intracratonic area which underwent sediment sag-loading in the Jurassic to Cretaceous.
== Stratigraphy == {{expand section|date=March 2020|The stratigraphy chapter does not list the stratigraphy of the basin, with an important fossiliferous formation as the Griman Creek Formation, that is unacceptable}} The western central parts of the Surat Basin [[Unconformity|unconformably]] overlies the [[Palaeozoic]] [[igneous]], [[Metamorphic rocks|metamorphic]] and [[sedimentary rocks]] of the [[Lachlan Fold Belt]]. [[File:Surat Basin protest.jpg|thumb|Primary producers are especially concerned with the environmental and economic impacts of the Basin's development, [[Dalby, Queensland|Dalby]], 2010]] 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]] in southern Queensland,<ref name="gab">{{cite web |url=http://www.ga.gov.au/oceans/ea_Browse.jsp |title=Geoscience Australia - Bowen Basin |author= |access-date=2009-09-22 |date=1 July 2008 |publisher=[[Commonwealth of Australia]] |url-status=dead |archive-url=https://web.archive.org/web/20091126012825/http://www.ga.gov.au/oceans/ea_Browse.jsp |archive-date=26 November 2009 |df=dmy-all }}</ref> and overlies the [[Gunnedah Basin]] 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,<ref name="gas"/> with up to 1,800 m preserved in New South Wales.
Deposition in the Surat Basin commenced in the Early Jurassic with the Precipice Sandstone, a quartzose blocky sandstone unit interpreted as being deposited in a Braided Stream environment.
the Precipice Sandstone is overlain by the finer grained and lower energy Evergreen formation. The Evergreen also contains local sand unit known as the Boxvale Sandstone.
The Evergreen is conformably overlain by the Hutton Sandstone, which in turn is overlain by the Walloon Coal Measures.
After a brief (although debated) hiatus, the Springbok Sandstone was deposited. It is unclear whether the thickness changes in the Walloon Coal Measures indicate a major erosional event (unconformity), or if the contact is only locally scoured.
The Springbok Sandstone grades upward into the Westbourne Formation. This contact is poorly defined, and still subject to debate.
The westbourne is then overlain progressively by the Gubbermunda Sandstone, Oralo Formation, Mooga Sandstone, Bungil Formation, Wallumbilla Formation, Surat Siltstone, and finally the Griman Creek Formation.
Later sediments have been removed by erosion since Cretaceous times.
==Economic geology== <!-- Deleted image removed: [[File:CoalFos1.jpg|thumb|Right|Fern fossils in silt parting from Jurassic coal measures within the Surat Basin]] --> Since the early 2000s the Coal Seam Gas has been produced from multiple fields. More than conventional 100 hydrocarbon accumulations have been found in the basin however only half are producing.<ref name="gas">{{cite web |url=http://www.ga.gov.au/oceans/ea_Surat.jsp |title=Geoscience Australia - Surat Basin |author= |access-date=2009-09-22 |date=1 July 2008 |publisher=[[Commonwealth of Australia]] |url-status=dead |archive-url=https://web.archive.org/web/20090207014814/http://www.ga.gov.au/oceans/ea_Surat.jsp |archive-date=7 February 2009 |df=dmy-all }}</ref> The Surat Basin is not very important a target for [[petroleum|oil]] as the [[source rock]]s have not generally been subjected to suitable conditions to evolve oil. There is some slight conventional natural gas potential. Jurassic [[coal]] 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.<ref>[http://www.nrw.qld.gov.au/mines/coal/pdf/world_class_coals_3.pdf Queensland's World-class Coals: Mine Production and Developments] {{Webarchive|url=https://web.archive.org/web/20070509051829/http://www.nrw.qld.gov.au/mines/coal/pdf/world_class_coals_3.pdf |date=9 May 2007 }} December 2005. Retrieved 19 April 2007.</ref>
===Coal Seam Gas=== The basin has a number of coal seam gas (CSG) fields - also known as [[coalbed methane]] - developing in the region. These fields presently supply both the domestic market, including a number of power stations and the [[Roma to Brisbane Pipeline]], and Liquified Natural Gas (LNG) Plants located on Curtis Island near [[Gladstone, Queensland|Gladstone]] to export Surat Basin gas to international markets. The [[Port of Gladstone]] is undergoing a [[Australian dollar|A$]]3.5 billion expansion to accommodate expected demands.<ref name="sbnbe">{{Cite news |url=http://www.theaustralian.com.au/business/property/surat-basin-to-become-one-of-the-nations-boom-economies/story-e6frg9gx-1225851134838 |title=Surat Basin to become one of the nation's boom economies |author=Terry Ryder |accessdate=11 October 2010 |date=8 April 2010 |work=[[The Australian]] |publisher=News Limited }}</ref> In 2010, two energy companies confirmed their mines have the potential to affect groundwater levels.<ref name="csgwl">{{Cite news |url=http://www.theaustralian.com.au/national-affairs/coal-seam-gas-may-cause-underground-water-level-may-fall-gas-firms-admit/story-fn59niix-1225936189929 |title=Coal-seam gas may cause Underground water level may fall, gas firms admit |author=Rosanne Barrett |accessdate=11 October 2010 |date=9 October 2010 |work=[[The Australian]] |publisher=News Limited |archive-date=10 October 2010 |archive-url=https://web.archive.org/web/20101010025708/http://www.theaustralian.com.au/national-affairs/coal-seam-gas-may-cause-underground-water-level-may-fall-gas-firms-admit/story-fn59niix-1225936189929 |url-status=live }}</ref>
==See also== {{Portal|Australia|Geology}} * [[Bituminous coal]] * [[Mining in Australia]] {{Clear}}
==References== {{Reflist}}
{{coord|30|50|36.93|S|149|30|03.29|E|display=title|region:AU_type:city_source:GNS-enwiki}}
[[Category:Geology of Queensland]] [[Category:Geology of New South Wales]] [[Category:Sedimentary basins of Australia]] [[Category:Coal mining regions in Australia]] [[Category:Natural gas in Queensland]] [[Category:Energy in New South Wales]]