Outboard Onset of Ross Orogen Magmatism and Subsequent Igneous and Metamorphic Cooling Linked to Slab Rollback during Late-Stage Gondwana Assembly
Changes in magmatism and sedimentation along the late Neoproterozoic-early Paleozoic Ross orogenic belt in Antarctica have been linked to the cessation of convergence along the Mozambique belt during the assembly of East-West Gondwana. However, these interpretations are non-unique and are based, in...
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ftethz:oai:www.research-collection.ethz.ch:20.500.11850/610928 2023-06-11T04:04:16+02:00 Outboard Onset of Ross Orogen Magmatism and Subsequent Igneous and Metamorphic Cooling Linked to Slab Rollback during Late-Stage Gondwana Assembly Paulsen, Timothy Encarnación, John Grunow, Anne Benowitz, Jeffrey Layer, Paul Deering, Chad Sliwinski, Jakub 2023-04 application/application/pdf https://hdl.handle.net/20.500.11850/610928 https://doi.org/10.3929/ethz-b-000610928 en eng MDPI info:eu-repo/semantics/altIdentifier/doi/10.3390/geosciences13040126 info:eu-repo/semantics/altIdentifier/wos/000979298500001 http://hdl.handle.net/20.500.11850/610928 doi:10.3929/ethz-b-000610928 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International Geosciences, 13 (4) 40Ar/39Ar cooling magmatism zircon trace elements slab rollback Ross orogen Antarctica Gondwana info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2023 ftethz https://doi.org/20.500.11850/61092810.3929/ethz-b-00061092810.3390/geosciences13040126 2023-05-28T23:50:10Z Changes in magmatism and sedimentation along the late Neoproterozoic-early Paleozoic Ross orogenic belt in Antarctica have been linked to the cessation of convergence along the Mozambique belt during the assembly of East-West Gondwana. However, these interpretations are non-unique and are based, in part, on limited thermochronological data sets spread out along large sectors of the East Antarctic margin. We report new 40Ar/39Ar hornblende, muscovite, and biotite age data for plutonic (n = 13) and metasedimentary (n = 3) samples from the Shackleton–Liv Glacier sector of the Queen Maud Mountains in Antarctica. Cumulative 40Ar/39Ar age data show polymodal age peaks (510 Ma, 491 Ma, 475 Ma) that lag peaks in U-Pb igneous crystallization ages, suggesting igneous and metamorphic cooling following magmatism within the region. The 40Ar/39Ar ages are similar to ages in other sectors of the Ross orogen, but younger than detrital mineral 40Ar/39Ar cooling ages indicative of older magmatism and cooling of unexposed inboard areas along the margin. Detrital zircon trace element abundances suggest that the widespread onset of magmatism in outboard localities of the orogen correlates with a ~560–530 Ma decrease in crustal thickness. The timing of crustal thinning recorded by zircon in magmas overlaps with other evidence for the timing of crustal extension, suggesting that the regional onset of magmatism with subsequent igneous and metamorphic cooling probably reflects slab rollback that coincided with possible global plate motion changes induced during the final assembly of Gondwana. ISSN:2076-3263 Article in Journal/Newspaper Antarc* Antarctic Antarctica Liv Glacier ETH Zürich Research Collection Antarctic Liv Glacier ENVELOPE(-168.000,-168.000,-84.917,-84.917) Shackleton |
institution |
Open Polar |
collection |
ETH Zürich Research Collection |
op_collection_id |
ftethz |
language |
English |
topic |
40Ar/39Ar cooling magmatism zircon trace elements slab rollback Ross orogen Antarctica Gondwana |
spellingShingle |
40Ar/39Ar cooling magmatism zircon trace elements slab rollback Ross orogen Antarctica Gondwana Paulsen, Timothy Encarnación, John Grunow, Anne Benowitz, Jeffrey Layer, Paul Deering, Chad Sliwinski, Jakub Outboard Onset of Ross Orogen Magmatism and Subsequent Igneous and Metamorphic Cooling Linked to Slab Rollback during Late-Stage Gondwana Assembly |
topic_facet |
40Ar/39Ar cooling magmatism zircon trace elements slab rollback Ross orogen Antarctica Gondwana |
description |
Changes in magmatism and sedimentation along the late Neoproterozoic-early Paleozoic Ross orogenic belt in Antarctica have been linked to the cessation of convergence along the Mozambique belt during the assembly of East-West Gondwana. However, these interpretations are non-unique and are based, in part, on limited thermochronological data sets spread out along large sectors of the East Antarctic margin. We report new 40Ar/39Ar hornblende, muscovite, and biotite age data for plutonic (n = 13) and metasedimentary (n = 3) samples from the Shackleton–Liv Glacier sector of the Queen Maud Mountains in Antarctica. Cumulative 40Ar/39Ar age data show polymodal age peaks (510 Ma, 491 Ma, 475 Ma) that lag peaks in U-Pb igneous crystallization ages, suggesting igneous and metamorphic cooling following magmatism within the region. The 40Ar/39Ar ages are similar to ages in other sectors of the Ross orogen, but younger than detrital mineral 40Ar/39Ar cooling ages indicative of older magmatism and cooling of unexposed inboard areas along the margin. Detrital zircon trace element abundances suggest that the widespread onset of magmatism in outboard localities of the orogen correlates with a ~560–530 Ma decrease in crustal thickness. The timing of crustal thinning recorded by zircon in magmas overlaps with other evidence for the timing of crustal extension, suggesting that the regional onset of magmatism with subsequent igneous and metamorphic cooling probably reflects slab rollback that coincided with possible global plate motion changes induced during the final assembly of Gondwana. ISSN:2076-3263 |
format |
Article in Journal/Newspaper |
author |
Paulsen, Timothy Encarnación, John Grunow, Anne Benowitz, Jeffrey Layer, Paul Deering, Chad Sliwinski, Jakub |
author_facet |
Paulsen, Timothy Encarnación, John Grunow, Anne Benowitz, Jeffrey Layer, Paul Deering, Chad Sliwinski, Jakub |
author_sort |
Paulsen, Timothy |
title |
Outboard Onset of Ross Orogen Magmatism and Subsequent Igneous and Metamorphic Cooling Linked to Slab Rollback during Late-Stage Gondwana Assembly |
title_short |
Outboard Onset of Ross Orogen Magmatism and Subsequent Igneous and Metamorphic Cooling Linked to Slab Rollback during Late-Stage Gondwana Assembly |
title_full |
Outboard Onset of Ross Orogen Magmatism and Subsequent Igneous and Metamorphic Cooling Linked to Slab Rollback during Late-Stage Gondwana Assembly |
title_fullStr |
Outboard Onset of Ross Orogen Magmatism and Subsequent Igneous and Metamorphic Cooling Linked to Slab Rollback during Late-Stage Gondwana Assembly |
title_full_unstemmed |
Outboard Onset of Ross Orogen Magmatism and Subsequent Igneous and Metamorphic Cooling Linked to Slab Rollback during Late-Stage Gondwana Assembly |
title_sort |
outboard onset of ross orogen magmatism and subsequent igneous and metamorphic cooling linked to slab rollback during late-stage gondwana assembly |
publisher |
MDPI |
publishDate |
2023 |
url |
https://hdl.handle.net/20.500.11850/610928 https://doi.org/10.3929/ethz-b-000610928 |
long_lat |
ENVELOPE(-168.000,-168.000,-84.917,-84.917) |
geographic |
Antarctic Liv Glacier Shackleton |
geographic_facet |
Antarctic Liv Glacier Shackleton |
genre |
Antarc* Antarctic Antarctica Liv Glacier |
genre_facet |
Antarc* Antarctic Antarctica Liv Glacier |
op_source |
Geosciences, 13 (4) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.3390/geosciences13040126 info:eu-repo/semantics/altIdentifier/wos/000979298500001 http://hdl.handle.net/20.500.11850/610928 doi:10.3929/ethz-b-000610928 |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International |
op_doi |
https://doi.org/20.500.11850/61092810.3929/ethz-b-00061092810.3390/geosciences13040126 |
_version_ |
1768386591434211328 |