Mantle upwelling after Gondwana subduction death explains anomalous topography and subsidence histories of eastern New Zealand and West Antarctica
West Antarctica and adjacent seafloor have topographic elevations 0.5–1.2 km greater than expected from models of lithospheric age and crustal structure. Ocean crust near New Zealand has no equivalent depth anomaly, but tectonic subsidence histories from Campbell Plateau petroleum wells show anoma...
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Geological Society of America
2010
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ftcaltechauth:oai:authors.library.caltech.edu:ezbbb-7ea04 2024-06-23T07:46:41+00:00 Mantle upwelling after Gondwana subduction death explains anomalous topography and subsidence histories of eastern New Zealand and West Antarctica Sutherland, Rupert Spasojevic, Sonja Gurnis, Michael 2010-02 https://doi.org/10.1130/G30613.1 unknown Geological Society of America https://doi.org/10.1130/G30613.1 oai:authors.library.caltech.edu:ezbbb-7ea04 eprintid:17575 resolverid:CaltechAUTHORS:20100224-111903665 info:eu-repo/semantics/closedAccess Other Geology, 38(2), 155-158, (2010-02) info:eu-repo/semantics/article 2010 ftcaltechauth https://doi.org/10.1130/G30613.1 2024-06-12T01:43:01Z West Antarctica and adjacent seafloor have topographic elevations 0.5–1.2 km greater than expected from models of lithospheric age and crustal structure. Ocean crust near New Zealand has no equivalent depth anomaly, but tectonic subsidence histories from Campbell Plateau petroleum wells show anomalously high subsidence rates during the Paleogene, and total subsidence 0.5–0.9 km greater than expected from rift basin models. Geophysical and geochemical anomalies suggest that upward mantle flow supports the anomalous topography beneath Antarctica, and the Campbell Plateau subsidence history indicates that topographic support mechanisms were long lived (>80 Ma) and recoverable over a period of ~30 m.y. as plate motions moved New Zealand from Antarctica. We construct models of Late Cretaceous and Cenozoic mantle flow with a slab graveyard and upwelling above that is initially rooted at 1000–1500 km depth. Our models match topography and subsidence history anomalies, and are consistent with mantle seismic wave speed anomalies and the geoid. We suggest that when thermally driven slab downwelling ceased ca. 100 Ma, low-density material that was fertilized within a broad zone in the lower mantle during the previous ~400 m.y. of Gondwana subduction was released and able to rise. Mantle upwelling from depths of 700–1500 km, lasting for periods of ~100–200 m.y., with enriched chemistry related to the prior subduction history may be a general process that follows subduction death, and has not previously been recognized. © 2010 Geological Society of America. Received 14 August 2009; accepted 9 September 2009. Funded by the New Zealand Foundation for Research Science and Technology and National Science Foundation grant EAR-0810303. Contribution 10027 of the Division of Geological and Planetary Sciences and contribution 118 of the Tectonics Observatory, California Institute of Technology. Article in Journal/Newspaper Antarc* Antarctica West Antarctica Caltech Authors (California Institute of Technology) Campbell Plateau ENVELOPE(171.000,171.000,-50.667,-50.667) New Zealand West Antarctica Geology 38 2 155 158 |
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Open Polar |
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Caltech Authors (California Institute of Technology) |
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ftcaltechauth |
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description |
West Antarctica and adjacent seafloor have topographic elevations 0.5–1.2 km greater than expected from models of lithospheric age and crustal structure. Ocean crust near New Zealand has no equivalent depth anomaly, but tectonic subsidence histories from Campbell Plateau petroleum wells show anomalously high subsidence rates during the Paleogene, and total subsidence 0.5–0.9 km greater than expected from rift basin models. Geophysical and geochemical anomalies suggest that upward mantle flow supports the anomalous topography beneath Antarctica, and the Campbell Plateau subsidence history indicates that topographic support mechanisms were long lived (>80 Ma) and recoverable over a period of ~30 m.y. as plate motions moved New Zealand from Antarctica. We construct models of Late Cretaceous and Cenozoic mantle flow with a slab graveyard and upwelling above that is initially rooted at 1000–1500 km depth. Our models match topography and subsidence history anomalies, and are consistent with mantle seismic wave speed anomalies and the geoid. We suggest that when thermally driven slab downwelling ceased ca. 100 Ma, low-density material that was fertilized within a broad zone in the lower mantle during the previous ~400 m.y. of Gondwana subduction was released and able to rise. Mantle upwelling from depths of 700–1500 km, lasting for periods of ~100–200 m.y., with enriched chemistry related to the prior subduction history may be a general process that follows subduction death, and has not previously been recognized. © 2010 Geological Society of America. Received 14 August 2009; accepted 9 September 2009. Funded by the New Zealand Foundation for Research Science and Technology and National Science Foundation grant EAR-0810303. Contribution 10027 of the Division of Geological and Planetary Sciences and contribution 118 of the Tectonics Observatory, California Institute of Technology. |
format |
Article in Journal/Newspaper |
author |
Sutherland, Rupert Spasojevic, Sonja Gurnis, Michael |
spellingShingle |
Sutherland, Rupert Spasojevic, Sonja Gurnis, Michael Mantle upwelling after Gondwana subduction death explains anomalous topography and subsidence histories of eastern New Zealand and West Antarctica |
author_facet |
Sutherland, Rupert Spasojevic, Sonja Gurnis, Michael |
author_sort |
Sutherland, Rupert |
title |
Mantle upwelling after Gondwana subduction death explains anomalous topography and subsidence histories of eastern New Zealand and West Antarctica |
title_short |
Mantle upwelling after Gondwana subduction death explains anomalous topography and subsidence histories of eastern New Zealand and West Antarctica |
title_full |
Mantle upwelling after Gondwana subduction death explains anomalous topography and subsidence histories of eastern New Zealand and West Antarctica |
title_fullStr |
Mantle upwelling after Gondwana subduction death explains anomalous topography and subsidence histories of eastern New Zealand and West Antarctica |
title_full_unstemmed |
Mantle upwelling after Gondwana subduction death explains anomalous topography and subsidence histories of eastern New Zealand and West Antarctica |
title_sort |
mantle upwelling after gondwana subduction death explains anomalous topography and subsidence histories of eastern new zealand and west antarctica |
publisher |
Geological Society of America |
publishDate |
2010 |
url |
https://doi.org/10.1130/G30613.1 |
long_lat |
ENVELOPE(171.000,171.000,-50.667,-50.667) |
geographic |
Campbell Plateau New Zealand West Antarctica |
geographic_facet |
Campbell Plateau New Zealand West Antarctica |
genre |
Antarc* Antarctica West Antarctica |
genre_facet |
Antarc* Antarctica West Antarctica |
op_source |
Geology, 38(2), 155-158, (2010-02) |
op_relation |
https://doi.org/10.1130/G30613.1 oai:authors.library.caltech.edu:ezbbb-7ea04 eprintid:17575 resolverid:CaltechAUTHORS:20100224-111903665 |
op_rights |
info:eu-repo/semantics/closedAccess Other |
op_doi |
https://doi.org/10.1130/G30613.1 |
container_title |
Geology |
container_volume |
38 |
container_issue |
2 |
container_start_page |
155 |
op_container_end_page |
158 |
_version_ |
1802647497247555584 |