Geochemistry and significance of basaltic rocks dredged from the South Tasman Rise and adjacent seamounts
Basalts dredged from two seamounts separated by some 200 km and built on ca 50-35 Ma oceanic crust west of Tasmania have slightly LREE-depleted N-MORB affinities and were probably generated in a spreading ridge or near-ridge setting. They are compositionally very similar to 60 Ma basalts drilled at...
Published in: | Australian Journal of Earth Sciences |
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Online Access: | https://doi.org/10.1080/08120099708728341 http://ecite.utas.edu.au/12111 |
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ftunivtasecite:oai:ecite.utas.edu.au:12111 2023-05-15T13:56:40+02:00 Geochemistry and significance of basaltic rocks dredged from the South Tasman Rise and adjacent seamounts Crawford, AJ Lanyon, R Elmes, M Eggins, SM 1997 https://doi.org/10.1080/08120099708728341 http://ecite.utas.edu.au/12111 en eng Blackwell http://dx.doi.org/10.1080/08120099708728341 Crawford, AJ and Lanyon, R and Elmes, M and Eggins, SM, Geochemistry and significance of basaltic rocks dredged from the South Tasman Rise and adjacent seamounts, Australian Journal of Earth Sciences, 44, (5) pp. 621-632. ISSN 0812-0099 (1997) [Refereed Article] http://ecite.utas.edu.au/12111 Earth Sciences Geology Igneous and Metamorphic Petrology Refereed Article PeerReviewed 1997 ftunivtasecite https://doi.org/10.1080/08120099708728341 2019-12-13T20:57:04Z Basalts dredged from two seamounts separated by some 200 km and built on ca 50-35 Ma oceanic crust west of Tasmania have slightly LREE-depleted N-MORB affinities and were probably generated in a spreading ridge or near-ridge setting. They are compositionally very similar to 60 Ma basalts drilled at DSDP Site 282, midway between these seamounts. Taken together, these basalts provide a useful dataset for the compositional features of MORB erupted early in the rifting history of Tasmania separating from Antarctica. Well-preserved intraplate alkaline basalts with HIMU geochemical affinities have been sampled from Cascade Seamount, which forms the peak of the East Tasman Plateau. Far more altered alkaline intraplate basalts dredged at several other locations within the South Tasman Rise south of Tasmania, and on seamounts built on oceanic crust and thinned continental crust south of the East Tasman Plateau, also show typically HIMU affinities for immobile trace-element ratios (e.g. low Zr/Nb values, 3-5), but have undergone strong rare-earth element mobility associated with sea-floor weathering and replacement of glass by chemisorbed biogenic phosphate. Dolerites with some strong affinities to the Jurassic dolerites of Tasmania were dredged in the central section of the South Tasman Rise. Article in Journal/Newspaper Antarc* Antarctica eCite UTAS (University of Tasmania) South Tasman Rise ENVELOPE(148.000,148.000,-47.500,-47.500) Australian Journal of Earth Sciences 44 5 621 632 |
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Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Geology Igneous and Metamorphic Petrology |
spellingShingle |
Earth Sciences Geology Igneous and Metamorphic Petrology Crawford, AJ Lanyon, R Elmes, M Eggins, SM Geochemistry and significance of basaltic rocks dredged from the South Tasman Rise and adjacent seamounts |
topic_facet |
Earth Sciences Geology Igneous and Metamorphic Petrology |
description |
Basalts dredged from two seamounts separated by some 200 km and built on ca 50-35 Ma oceanic crust west of Tasmania have slightly LREE-depleted N-MORB affinities and were probably generated in a spreading ridge or near-ridge setting. They are compositionally very similar to 60 Ma basalts drilled at DSDP Site 282, midway between these seamounts. Taken together, these basalts provide a useful dataset for the compositional features of MORB erupted early in the rifting history of Tasmania separating from Antarctica. Well-preserved intraplate alkaline basalts with HIMU geochemical affinities have been sampled from Cascade Seamount, which forms the peak of the East Tasman Plateau. Far more altered alkaline intraplate basalts dredged at several other locations within the South Tasman Rise south of Tasmania, and on seamounts built on oceanic crust and thinned continental crust south of the East Tasman Plateau, also show typically HIMU affinities for immobile trace-element ratios (e.g. low Zr/Nb values, 3-5), but have undergone strong rare-earth element mobility associated with sea-floor weathering and replacement of glass by chemisorbed biogenic phosphate. Dolerites with some strong affinities to the Jurassic dolerites of Tasmania were dredged in the central section of the South Tasman Rise. |
format |
Article in Journal/Newspaper |
author |
Crawford, AJ Lanyon, R Elmes, M Eggins, SM |
author_facet |
Crawford, AJ Lanyon, R Elmes, M Eggins, SM |
author_sort |
Crawford, AJ |
title |
Geochemistry and significance of basaltic rocks dredged from the South Tasman Rise and adjacent seamounts |
title_short |
Geochemistry and significance of basaltic rocks dredged from the South Tasman Rise and adjacent seamounts |
title_full |
Geochemistry and significance of basaltic rocks dredged from the South Tasman Rise and adjacent seamounts |
title_fullStr |
Geochemistry and significance of basaltic rocks dredged from the South Tasman Rise and adjacent seamounts |
title_full_unstemmed |
Geochemistry and significance of basaltic rocks dredged from the South Tasman Rise and adjacent seamounts |
title_sort |
geochemistry and significance of basaltic rocks dredged from the south tasman rise and adjacent seamounts |
publisher |
Blackwell |
publishDate |
1997 |
url |
https://doi.org/10.1080/08120099708728341 http://ecite.utas.edu.au/12111 |
long_lat |
ENVELOPE(148.000,148.000,-47.500,-47.500) |
geographic |
South Tasman Rise |
geographic_facet |
South Tasman Rise |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_relation |
http://dx.doi.org/10.1080/08120099708728341 Crawford, AJ and Lanyon, R and Elmes, M and Eggins, SM, Geochemistry and significance of basaltic rocks dredged from the South Tasman Rise and adjacent seamounts, Australian Journal of Earth Sciences, 44, (5) pp. 621-632. ISSN 0812-0099 (1997) [Refereed Article] http://ecite.utas.edu.au/12111 |
op_doi |
https://doi.org/10.1080/08120099708728341 |
container_title |
Australian Journal of Earth Sciences |
container_volume |
44 |
container_issue |
5 |
container_start_page |
621 |
op_container_end_page |
632 |
_version_ |
1766264227827286016 |