Australia Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.Anti-spam check. Do not fill this in! ===Geology=== {{Main|Geology of Australia}} [[File:Ausgeolbasic.jpg|thumb|upright=1.2|right|Basic geological regions of Australia, by age]] Lying on the [[Indo-Australian Plate]], the mainland of Australia is the lowest and most primordial landmass on Earth with a relatively stable geological history.<ref>Pirajno, F., Occhipinti, S.A. and Swager, C.P., 1998. ''Geology and tectonic evolution of the Palaeoproterozoic Bryah, Padbury and Yerrida basins, Western Australia: implications for the history of the south-central Capricorn orogen'' Precambrian Research, 90: 119β40</ref><ref>Pain, C.F., Villans, B.J., Roach, I.C., Worrall, L. & Wilford, J.R. (2012) "Old, flat and red β Australia's distinctive landscape" In: ''Shaping a Nation: A Geology of Australia'' Blewitt, R.S. (Ed.) Geoscience Australia and ANU E Press, Canberra. pp. 227β75 {{ISBN|978-1-9221-0343-7}}</ref> The landmass includes virtually all known rock types and from all geological time periods spanning over 3.8 billion years of the Earth's history. The [[Pilbara Craton]] is one of only two pristine [[Archean|Archaean]] 3.6β2.7 Ga (billion years ago) crusts identified on the Earth.<ref>{{Cite journal|last1=Gray|first1=DR|last2=Foster|first2=DA|year=2004 |title=Tectonic review of the Lachlan Orogen: historical review, data synthesis and modern perspectives|journal=Australian Journal of Earth Sciences|volume=51|issue=6|pages=773β817|doi=10.1111/j.1400-0952.2004.01092.x|s2cid=128901742}}</ref> Having been part of all major [[supercontinent]]s, the [[Australia (continent)|Australian continent]] began to form after the breakup of [[Gondwana]] in the [[Permian]], with the separation of the continental landmass from the African continent and Indian subcontinent. It separated from Antarctica over a prolonged period beginning in the [[Permian]] and continuing through to the [[Cretaceous]].<ref>{{Cite journal|last1=Hawkesworth|first1=CJ|display-authors=et al.|year=2010 |title=The generation and evolution of the continental crust|journal=Journal of the Geological Society|volume=167|issue=2|pages=229β248 |doi=10.1144/0016-76492009-072|bibcode=2010JGSoc.167..229H|s2cid=131052922}}</ref> When the [[last glacial period]] ended in about 10,000 BC, rising sea levels formed [[Bass Strait]], separating [[Tasmania]] from the mainland. Then between about 8,000 and 6,500 BC, the lowlands in the north were flooded by the sea, separating New Guinea, the [[Aru Islands]], and the mainland of Australia.<ref>Hillis RR & Muller RD. (eds) 2003 ''Evolution and dynamics of the Australian Plate'' Geological Society of Australia Special Publication 22: 432 p.</ref> The Australian continent is moving toward [[Eurasia]] at the rate of 6 to 7 centimetres a year.<ref>{{Cite journal|last1=Cawood|first1=PA|year=2005 |title=Terra Australis Orogen: ''Rodinia breakup and development of the Pacific and Iapetus margins of Gondwana during the Neoproterozoic and Paleozoic''|journal=Earth-Science Reviews|volume=69|issue=3β4|pages=249β279|doi=10.1016/j.earscirev.2004.09.001|bibcode=2005ESRv...69..249C}}</ref> The Australian mainland's [[continental crust]], excluding the thinned margins, has an average thickness of 38{{Nbsp}}km, with a range in thickness from 24 km to 59 km.<ref>McKenzie et al. (ed) 2004 Australian Soils and Landscapes: an illustrated compendium [[CSIRO]] Publishing: 395 p.</ref> Australia's geology can be divided into several main sections, showcasing that the continent grew from west to east: the Archaean [[craton]]ic shields found mostly in the west, [[Proterozoic]] [[orogeny|fold belts]] in the centre and [[Phanerozoic]] [[sedimentary basins]], metamorphic and [[igneous rocks]] in the east.<ref>Bishop P & Pillans B. (eds) 2010, Australian Landscapes Geological Society of London Special Publication 346</ref> The Australian mainland and Tasmania are situated in the middle of the [[tectonic plate]] and have no active volcanoes,<ref name="ag">{{Cite web |url=http://www.australiangeographic.com.au/journal/land-of-earthquakes-and-volcanoes.htm |title=Land of earthquakes and volcanoes?|first=Kevin|last=Mccue |access-date=25 April 2010|date=26 February 2010|publisher=Australian Geographic |url-status=dead |archive-url=https://web.archive.org/web/20100306150520/http://www.australiangeographic.com.au/journal/land-of-earthquakes-and-volcanoes.htm |archive-date=6 March 2010}}</ref> but due to passing over the [[East Australia hotspot]], recent volcanism has occurred during the [[Holocene]], in the [[Newer Volcanics Province]] of western Victoria and south-eastern South Australia. Volcanism also occurs in the island of New Guinea (considered geologically as part of the Australian continent), and in the Australian external territory of [[Heard Island and McDonald Islands]].<ref>Van Ufford AQ & Cloos M. 2005 ''Cenozoic tectonics of New Guinea'' AAPG Bulletin 89: 119β140</ref> [[List of earthquakes in Australia|Seismic activity]] in the Australian mainland and Tasmania is also low, with the greatest number of fatalities having occurred in the [[1989 Newcastle earthquake]].<ref>{{Cite web |url=http://www.ga.gov.au/urban/factsheets/earthquakes_newcastle.jsp |title=Earthquake History, Regional Seismicity And The 1989 Newcastle Earthquake |publisher=Geoscience Australia|date=22 June 2004 |access-date=27 June 2007 |archive-url=https://web.archive.org/web/20040826220212/http://www.ga.gov.au/urban/factsheets/earthquakes_newcastle.jsp |archive-date=26 August 2004}}</ref> Summary: Please note that all contributions to Christianpedia may be edited, altered, or removed by other contributors. 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