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SphericalSong (talk | contribs) Edited to give a more accurate picture of scientists' views about the cause of volcanism |
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[[Image:Hotspots.jpg|right|thumb|350px|The East Australia hotspot is marked 30 on map.]] |
[[Image:Hotspots.jpg|right|thumb|350px|The East Australia hotspot is marked 30 on map.]] |
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[[Image:Mtschank.jpg|thumb|right|250px|View inside the [[volcanic crater|crater]] of [[Mount Schank]] from the rim]] |
[[Image:Mtschank.jpg|thumb|right|250px|View inside the [[volcanic crater|crater]] of [[Mount Schank]] from the rim]] |
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⚫ | The '''East Australia hotspot''' is a volcanic province in southeast [[Australia]] which includes the Peak Range in central [[Queensland]], the [[Main Range National Park|Main Range]] on the Queensland-[[New South Wales]] border, [[Tweed Volcano]] in New South Wales, and the [[Newer Volcanics Province]] (NVP) in [[South Australia]]. A number of the volcanoes in the province have erupted since Aboriginal settlement (46,000 BP). The most recent eruptions were about 5,600 years ago, and memories of them survive in Aboriginal folklore. These eruptions formed the volcanoes [[Mount Schank]] and [[Mount Gambier (volcano)|Mount Gambier]] in the NVP. There have been no eruptions on the Australian mainland since European settlement. |
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The '''East Australia hotspot''' is a volcanic [[Hotspot (geology)|hotspot]] that forces [[magma]] up at weak spots in the [[Indo-Australian Plate]] to form [[volcano]]es in [[Eastern Australia]]. It does not produce a single chain of volcanoes like the [[Hawaiian Islands]].<ref name="Oregon State">[http://volcano.oregonstate.edu/vwdocs/volc_images/australia/volc_australia.html "Volcanoes of Australia"]. Volcano World, Department of Geosciences at Oregon State University. Retrieved 24 January 2010.</ref> Unlike most hotspots, the East Australia hotspot has explosive eruptions, as well as the runny [[lava flow]]s of the [[Hawaiian Islands#Geology|Hawaii hotspot]], the [[Iceland hotspot]] and the [[Réunion hotspot]]. The hotspot is explosive because [[basalt]]ic [[magma]] interacts with groundwater in aquifers below the surface producing violent [[phreatomagmatic eruptions]]. |
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Unlike most [[Hotspot (geology)|hotspots]], the East Australia hotspot has explosive eruptions as well as the runny [[lava flow]]s of the [[Hawaii hotspot]], the [[Iceland hotspot]] and the [[Réunion hotspot]]. The hotspot is thought to be explosive because [[basalt]]ic [[magma]] interacts with groundwater in aquifers below the surface producing violent [[phreatomagmatic eruptions]].<ref name=“Cas2017”>{{cite book |last1=Cas |first1=R.A.F. |last2=van Otterloo |first2=J. |last3=Blaikie |first3=T.N. |last4=van den Hove |first4=J. |editor-last1=Németh |editor-first1=K. |editor-last2=Carrasco-Núñez |editor-first2=G. |editor-last3=Aranda-Gómez |editor-first3=J.J. |editor-last4=Smith |editor-first4=I.E.M. |title=Monogenetic volcanism. Geological Society, London, Special Publications, 446 |publisher=Geological Society of London |date=2017 |pages=123-172 |chapter=The dynamics of a very large intra-plate continental basaltic volcanic province, the Newer Volcanics Province, SE Australia, and implications for other provinces |doi=10.1144/SP446.8}}</ref> |
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[[Tweed Volcano]] in [[New South Wales]] is a large [[shield volcano]] that was formed by the hotspot about 23 million years ago and has one of the biggest erosion [[caldera]]s in the world. |
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The cause of volcanism in the area is uncertain. Theories typically fall into one of two categories: the [[mantle plume]] theory and the [[Plate theory (volcanism)|plate theory]]. On the basis of the long duration of volcanic activity, its vast lateral extent, [[geochemistry]] of lavas, and [[Seismology|Seismic]], it has been proposed that the region is underlain by one or more deep mantle plumes which have forced [[magma]] up through points of weakness in the [[Indo-Australian Plate]] as it has moved northward over the source.<ref name=“Sutherland1991”>{{cite book |last=Sutherland |first=F.L. |editor-last1=DeDeckker |editor-first1=P. |editor-last2=Kershaw |editor-first2=A.P. |title=The Cainozoic in Australia: A re-appraisal of the evidence. Geological Society of Australia, Special Publications, 18|publisher=Geological Society of Australia |date=1991 |pages=15-43 |chapter=Cainozoic volcanism, Eastern Australian: a predictive model on migration over multiple ‘hotspot’ magma sources |isbn=0-909869-76-6}}</ref><ref name=“Graeber2002”>{{cite journal |last1=Graeber |first1=F.M. |last2=Houseman |first2=G.A. |last3=Greenhalgh |first3=S.A. |date=2002 |title=Regional teleseismic tomography of the western Lachlan Orogen and the Newer Volcanic Province, southeast Australia |url=https://academic.oup.com/gji/article/149/2/249/725934?login=true |journal=Geophysical Journal International |volume=149 |issue=2 |pages=249-266 |doi=10.1046/j.1365-246X.2002.01598.x}}</ref><ref name=“Montelli2006”>{{cite journal |last1=Montelli |first1=R. |last2=Nolet |first2=G. |last3=Dahlen |first3=F.A. |last4=Masters |first4=G. |date=2006 |title=A catalogue of deep mantle plumes: New results from finite‐frequency tomography |url=https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2006GC001248 |journal=Geochemistry, Geophysics, Geosystems |volume=7 |issue=11 |doi=10.1029/2006GC001248}}</ref><ref name=“JonVer2015”>{{cite journal |last1=Jones |first1=I. |last2=Verdel |first2=C. |date=2015 |title=Basalt distribution and volume estimates of Cenozoic volcanism in the Bowen Basin region of eastern Australia: Implications for a waning mantle plume |url=https://www.tandfonline.com/doi/full/10.1080/08120099.2015.997796?scroll=top&needAccess=true |journal=Australian Journal of Earth Sciences |volume=62 |issue=2 |pages=255-263 |doi=10.1080/08120099.2015.997796}}</ref> |
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⚫ | A number of the volcanoes in the province have erupted since Aboriginal settlement (46,000 BP). The most recent eruptions were about 5,600 years ago, and memories of them survive in Aboriginal folklore. These eruptions formed the volcanoes [[Mount Schank]] and [[Mount Gambier (volcano)|Mount Gambier]] in the |
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Several observations, however, such as the lack of clear age progression across much of the province and the orientation of the NVP which is orthogonal to plate motion, are inconsistent with plume models.<ref name=“Cas2017”/> Seismic anomalies, moreover, terminate at a depth of around 200 km, making the presence of a mantle plume unlikely.<ref name=“Davies2014”>{{cite journal |last1=Davies |first1=D.R. |last2=Rawlinson |first2=N. |date=2014 |title=On the origin of recent intraplate volcanism in Australia |url=https://pubs.geoscienceworld.org/gsa/geology/article-standard/42/12/1031/131405/On-the-origin-of-recent-intraplate-volcanism-in |journal=Geology |volume=42 |issue=12 |pages=1031-1034 |doi=10.1130/G36093.1}}</ref> |
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In opposition to plume models, various tectonic causes have been proposed. Some studies have argued that volcanic activity results from a combination of edge-driven convection (small-scale, shallow [[mantle convection]] caused by a change in lithospheric thickness at the continental margin where thick continental [[lithosphere]] meets thinner oceanic lithosphere) and decompression of the crust from normal faulting caused by plate stresses.<ref name=“Cas2017”/><ref name=“Davies2014”/> Another view is that extension from stresses brought about by changes in plate boundary configurations has caused severe lithospheric thinning resulting in decompression melting of the [[asthenosphere]].<ref name=“Aivazpourporgou2015”>{{cite journal |last1=Aivazpourporgou |first1=S. |last2=Thiel |first2=S. |last3=Hayman |first3=P.C. |last4=Moresi |first4=L.N. |last5=Heinson | first5=G. |date=2015 |title=Decompression melting driving intraplate volcanism in Australia: Evidence from magnetotelluric sounding |url=https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014GL060088 |journal=Geophysical Research Letters |volume=42 |issue=2 |pages=346-354 |doi=10.1002/2014GL060088}}</ref> Both of these models invoke shallow processes closely related to the operation of [[plate tectonics]] and so fall under the plate theory.<ref name=“FoulNat2003”>{{cite journal |last1=Foulger |first1=G.R. |last2=Natland |first2=J.H. |date=2003 |title=Is "hotspot" volcanism a consequence of plate tectonics? |url=https://science.sciencemag.org/content/300/5621/921|journal=Science |volume=300 |issue=5621 |pages=921-922 |doi= 10.1126/science.1083376}}</ref><ref name=“Foulger2007”>{{cite book |last=Foulger |first=G.R. |editor-last1=Foulger |editor-first1=G.R. |editor-last2=Jurdy |editor-first2=D.M. |title=Plates, plumes, and planetary processes: Geological Society of America Special Paper 430 |publisher=The Geological Society of America |date=2007 |pages=1-28 |chapter=The ‘plate’ model for the genesis of melting anomalies |isbn=978-0813724300}}</ref> Other models combine both plume and plate-tectonic processes.<ref name=“Holt2014”>{{cite journal |last1=Holt |first1=S.J. |last2=Holford |first2=S.P. |last3=Foden |first3=J. |date=2014 |title=New insights into the magmatic plumbing system of the South Australian Quaternary Basalt province from 3D seismic and geochemical data |url=https://www.tandfonline.com/doi/abs/10.1080/08120099.2013.865143 |journal=Australian Journal of Earth Sciences |volume=60 |issue=8 |pages=797-817 |doi=10.1080/08120099.2013.865143}}</ref><ref name=“Davies2015”>{{cite journal |last1=Davies |first1=D. |last2=Rawlinson |first2=N. |last3=Iaffaldano |first3=G. |last4=Campbell |first4=I.H. |date=2015 |title=Lithospheric controls on magma composition along Earth’s longest continental hotspot track |url=https://www.nature.com/articles/nature14903 |journal=Nature |volume=525 |pages=511-514 |doi=10.1038/nature14903}}</ref><ref name=“Rawlinson2017”>{{cite journal |last1=Rawlinson |first1=N. |last2=Davies |first2=D.R. |last3=Pilia |first3=S. |date=2017 |title=The mechanisms underpinning Cenozoic intraplate volcanism in eastern Australia: Insights from seismic tomography and geodynamic modeling |url= |journal=Geophysical Research Letters |volume=44 |issue=19 |pages=9681-9690 |doi=10.1002/2017GL074911}}</ref> |
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==See also== |
==See also== |
Revision as of 17:01, 3 February 2021
The East Australia hotspot is a volcanic province in southeast Australia which includes the Peak Range in central Queensland, the Main Range on the Queensland-New South Wales border, Tweed Volcano in New South Wales, and the Newer Volcanics Province (NVP) in South Australia. A number of the volcanoes in the province have erupted since Aboriginal settlement (46,000 BP). The most recent eruptions were about 5,600 years ago, and memories of them survive in Aboriginal folklore. These eruptions formed the volcanoes Mount Schank and Mount Gambier in the NVP. There have been no eruptions on the Australian mainland since European settlement.
Unlike most hotspots, the East Australia hotspot has explosive eruptions as well as the runny lava flows of the Hawaii hotspot, the Iceland hotspot and the Réunion hotspot. The hotspot is thought to be explosive because basaltic magma interacts with groundwater in aquifers below the surface producing violent phreatomagmatic eruptions.[1]
The cause of volcanism in the area is uncertain. Theories typically fall into one of two categories: the mantle plume theory and the plate theory. On the basis of the long duration of volcanic activity, its vast lateral extent, geochemistry of lavas, and Seismic, it has been proposed that the region is underlain by one or more deep mantle plumes which have forced magma up through points of weakness in the Indo-Australian Plate as it has moved northward over the source.[2][3][4][5]
Several observations, however, such as the lack of clear age progression across much of the province and the orientation of the NVP which is orthogonal to plate motion, are inconsistent with plume models.[1] Seismic anomalies, moreover, terminate at a depth of around 200 km, making the presence of a mantle plume unlikely.[6]
In opposition to plume models, various tectonic causes have been proposed. Some studies have argued that volcanic activity results from a combination of edge-driven convection (small-scale, shallow mantle convection caused by a change in lithospheric thickness at the continental margin where thick continental lithosphere meets thinner oceanic lithosphere) and decompression of the crust from normal faulting caused by plate stresses.[1][6] Another view is that extension from stresses brought about by changes in plate boundary configurations has caused severe lithospheric thinning resulting in decompression melting of the asthenosphere.[7] Both of these models invoke shallow processes closely related to the operation of plate tectonics and so fall under the plate theory.[8][9] Other models combine both plume and plate-tectonic processes.[10][11][12]
See also
References
- ^ a b c Cas, R.A.F.; van Otterloo, J.; Blaikie, T.N.; van den Hove, J. (2017). "The dynamics of a very large intra-plate continental basaltic volcanic province, the Newer Volcanics Province, SE Australia, and implications for other provinces". In Németh, K.; Carrasco-Núñez, G.; Aranda-Gómez, J.J.; Smith, I.E.M. (eds.). Monogenetic volcanism. Geological Society, London, Special Publications, 446. Geological Society of London. pp. 123–172. doi:10.1144/SP446.8.
- ^ Sutherland, F.L. (1991). "Cainozoic volcanism, Eastern Australian: a predictive model on migration over multiple 'hotspot' magma sources". In DeDeckker, P.; Kershaw, A.P. (eds.). The Cainozoic in Australia: A re-appraisal of the evidence. Geological Society of Australia, Special Publications, 18. Geological Society of Australia. pp. 15–43. ISBN 0-909869-76-6.
- ^ Graeber, F.M.; Houseman, G.A.; Greenhalgh, S.A. (2002). "Regional teleseismic tomography of the western Lachlan Orogen and the Newer Volcanic Province, southeast Australia". Geophysical Journal International. 149 (2): 249–266. doi:10.1046/j.1365-246X.2002.01598.x.
- ^ Montelli, R.; Nolet, G.; Dahlen, F.A.; Masters, G. (2006). "A catalogue of deep mantle plumes: New results from finite‐frequency tomography". Geochemistry, Geophysics, Geosystems. 7 (11). doi:10.1029/2006GC001248.
- ^ Jones, I.; Verdel, C. (2015). "Basalt distribution and volume estimates of Cenozoic volcanism in the Bowen Basin region of eastern Australia: Implications for a waning mantle plume". Australian Journal of Earth Sciences. 62 (2): 255–263. doi:10.1080/08120099.2015.997796.
- ^ a b Davies, D.R.; Rawlinson, N. (2014). "On the origin of recent intraplate volcanism in Australia". Geology. 42 (12): 1031–1034. doi:10.1130/G36093.1.
- ^ Aivazpourporgou, S.; Thiel, S.; Hayman, P.C.; Moresi, L.N.; Heinson, G. (2015). "Decompression melting driving intraplate volcanism in Australia: Evidence from magnetotelluric sounding". Geophysical Research Letters. 42 (2): 346–354. doi:10.1002/2014GL060088.
- ^ Foulger, G.R.; Natland, J.H. (2003). "Is "hotspot" volcanism a consequence of plate tectonics?". Science. 300 (5621): 921–922. doi:10.1126/science.1083376.
- ^ Foulger, G.R. (2007). "The 'plate' model for the genesis of melting anomalies". In Foulger, G.R.; Jurdy, D.M. (eds.). Plates, plumes, and planetary processes: Geological Society of America Special Paper 430. The Geological Society of America. pp. 1–28. ISBN 978-0813724300.
- ^ Holt, S.J.; Holford, S.P.; Foden, J. (2014). "New insights into the magmatic plumbing system of the South Australian Quaternary Basalt province from 3D seismic and geochemical data". Australian Journal of Earth Sciences. 60 (8): 797–817. doi:10.1080/08120099.2013.865143.
- ^ Davies, D.; Rawlinson, N.; Iaffaldano, G.; Campbell, I.H. (2015). "Lithospheric controls on magma composition along Earth's longest continental hotspot track". Nature. 525: 511–514. doi:10.1038/nature14903.
- ^ Rawlinson, N.; Davies, D.R.; Pilia, S. (2017). "The mechanisms underpinning Cenozoic intraplate volcanism in eastern Australia: Insights from seismic tomography and geodynamic modeling". Geophysical Research Letters. 44 (19): 9681–9690. doi:10.1002/2017GL074911.
External links