South Tasman Rise: Difference between revisions
Pbsouthwood (talk | contribs) Adding short description: "An area of seafloor about 1500 m deep south of Hobart, Tasmania in the Southern Ocean" (Shortdesc helper) |
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This area of the [[seafloor]] is slated for exploration of offshore [[mineral oil|oil]] reserves. No oil has been recovered from the South Tasman Rise.<ref name="pp21c">{{cite book |title=Petroleum Provinces of the 21st Century |author=The American Association of Petroleum Geologists |year=2001 |isbn=0-89181-355-1 |page=301 |url=https://books.google.com/books?id=i9jts14tq1gC |accessdate=22 December 2011}}</ref> |
This area of the [[seafloor]] is slated for exploration of offshore [[mineral oil|oil]] reserves. No oil has been recovered from the South Tasman Rise.<ref name="pp21c">{{cite book |title=Petroleum Provinces of the 21st Century |author=The American Association of Petroleum Geologists |year=2001 |isbn=0-89181-355-1 |page=301 |url=https://books.google.com/books?id=i9jts14tq1gC |accessdate=22 December 2011}}</ref> |
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===Rocks=== |
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A quartz syenite sample has an age of 1119 Ma which is [[Grenville (geology)]] in age. This kind of rock resembles rocks from the [[Grenville magmatic province]] in the west of the United States. It supports the idea that [[Laurentia]] and eastern Australia, including the South Tasman Rise were once joined to each other during the time of the [[Rodinia]] [[supercontinent]].<ref name="Fioretti2005">{{cite journal|last=Fioretti|first=A.M.|coauthors=L.P. Black, J. Foden, D. Visonà|year=2005|title=Grenville-age magmatism at the South Tasman Rise (Australia): A new piercing point for the reconstruction of Rodinia|journal=Geology|volume=33|issue=10|page=769|issn=0091-7613|doi=10.1130/G21671.1}}</ref> |
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Dolerite similar to the Jurassic dolerite in Tasmania has been recovered by dredging from the centre of the South Tasman Rise on ''RV Rig Seismic'' on its cruise 147.<ref name="Crawford1997">{{cite journal|last=Crawford|first=A. J.|coauthors=R. Lanyon, M. Elmes, S. Eggins|year=1997|title=Geochemistry and significance of basaltic rocks dredged from the South Tasman Rise and adjacent seamounts|journal=Australian Journal of Earth Sciences|volume=44|issue=5|pages=621–632|issn=0812-0099|doi=10.1080/08120099708728341}}</ref> |
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''[[Glomar Challenger]]'' drilled a borehole on the southern slope of STR.<ref name="Crawford1997"/> Hole 280 in oceanic crust resulted in basaltic intrusive of age 64.2 Ma. The hole at site 281 resulted in Precambrian quartz mica schist.<ref name="Crawford1997"/> |
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''RV Sonne'' did a cruise titled SO-36B in 1985 which did seismic profiles.<ref name="Hinz1990">{{cite journal|last=Hinz|first=K.|coauthors=M. Hemmerich, U. Salge, O. Eiken|year=1990|title=Structures in Rift — Basin Sediments on the Conjugate Margins of Western Tasmania, South Tasman Rise, and Ross Sea, Antarctica|pages=119–130|doi=10.1007/978-94-009-2029-3_7}}</ref> |
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===Tertiary sediments=== |
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Bottle green coloured [[microtectites]] were found in borehole 1169 at around early [[Pliocene]] age, 202.14 meters below the seabed.<ref name="KELLY2004"/> |
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==Fishery== |
==Fishery== |
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Revision as of 11:43, 4 January 2020
The South Tasman Rise is an area of seafloor that lies 550 km south of Hobart, Tasmania in the Southern Ocean where water depths are about 1,500 metres. The South Tasman Rise is also known as the Tasmania Ridge or South Tasmania Ridge.
Geology
The rise forms a northern extension from the Macquarie-Balleny Ridge which extends to the subantarctic Balleny Islands. To east of the rise is the Tasman Basin, while the South Australian Basin extends westwards, south of the Great Australian Bight. The rise contains a number of seamounts, some of which have flat summits, indicating exposure above the sea surface at some time.[1]
The rise most probably originates from subsided continental crust that fragmented as Australia and Antarctica separated.[2]
This area of the seafloor is slated for exploration of offshore oil reserves. No oil has been recovered from the South Tasman Rise.[3]
Rocks
A quartz syenite sample has an age of 1119 Ma which is Grenville (geology) in age. This kind of rock resembles rocks from the Grenville magmatic province in the west of the United States. It supports the idea that Laurentia and eastern Australia, including the South Tasman Rise were once joined to each other during the time of the Rodinia supercontinent.[4]
Dolerite similar to the Jurassic dolerite in Tasmania has been recovered by dredging from the centre of the South Tasman Rise on RV Rig Seismic on its cruise 147.[5]
Glomar Challenger drilled a borehole on the southern slope of STR.[5] Hole 280 in oceanic crust resulted in basaltic intrusive of age 64.2 Ma. The hole at site 281 resulted in Precambrian quartz mica schist.[5]
RV Sonne did a cruise titled SO-36B in 1985 which did seismic profiles.[6]
Tertiary sediments
Bottle green coloured microtectites were found in borehole 1169 at around early Pliocene age, 202.14 meters below the seabed.[7]
Fishery
The rise forms a sector of an international fishery managed by Australia and New Zealand.[8] New Zealand ceased fishing the area in the 2000-01 fishing season. By agreement between New Zealand and Australia the zone has been closed to commercial fishing since 2007. The principal species of fish sought after are the Orange Roughy and Oreo Dory using deepwater demersal trawlers.[9]
Marine reserve
The South Tasman Rise Commonwealth Marine Reserve was declared in 2007.[1] The reserve seeks to protect unique environments for marine life which are of significant scientific interest.
See also
References
- ^ a b "South Tasman Rise Commonwealth Marine Reserve". Department of Sustainability, Environment, Water, Population and Communities. 29 June 2011. Retrieved 22 December 2011.
- ^ Glassby, G.P., ed. (1990). "Structure and Tectonics". Antarctic Sector of the Pacific. Amsterdam, The Netherlands: Elsevier Science Publishers. p. 153. ISBN 0-444-88510-2. Retrieved 22 December 2011.
- ^ The American Association of Petroleum Geologists (2001). Petroleum Provinces of the 21st Century. p. 301. ISBN 0-89181-355-1. Retrieved 22 December 2011.
- ^ Fioretti, A.M. (2005). "Grenville-age magmatism at the South Tasman Rise (Australia): A new piercing point for the reconstruction of Rodinia". Geology. 33 (10): 769. doi:10.1130/G21671.1. ISSN 0091-7613.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ a b c Crawford, A. J. (1997). "Geochemistry and significance of basaltic rocks dredged from the South Tasman Rise and adjacent seamounts". Australian Journal of Earth Sciences. 44 (5): 621–632. doi:10.1080/08120099708728341. ISSN 0812-0099.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Hinz, K. (1990). "Structures in Rift — Basin Sediments on the Conjugate Margins of Western Tasmania, South Tasman Rise, and Ross Sea, Antarctica": 119–130. doi:10.1007/978-94-009-2029-3_7.
{{cite journal}}: Cite journal requires|journal=(help); Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Cite error: The named reference
KELLY2004was invoked but never defined (see the help page). - ^ "The Southern Remote Zone – South Tasman Rise Sector". Australian Fisheries Management Authority. Retrieved 22 December 2011.
- ^ "South Tasman Rise : At a Glance". Australian Fisheries Management Authority. Retrieved 22 December 2011.