Geochemical and isotopic composition of Bransfield Basin Lavas collected during SONNE cruise SO155
Bransfield Basin is an actively extending marginal basin separating the inactive South Shetland arc from the northern Antarctic Peninsula. Rift-related volcanism is widespread throughout the central Bransfield Basin, but the wider eastern Bransfield Basin was previously unsampled. Lavas recovered fr...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.847724 2024-09-15T17:42:11+00:00 Geochemical and isotopic composition of Bransfield Basin Lavas collected during SONNE cruise SO155 Fretzdorff, Susanne Worthington, Tim J Haase, Karsten M Hekinian, Roger Franz, Leander Keller, Randall A Stoffers, Peter MEDIAN LATITUDE: -61.979642 * MEDIAN LONGITUDE: -56.328732 * SOUTH-BOUND LATITUDE: -62.192300 * WEST-BOUND LONGITUDE: -57.277700 * NORTH-BOUND LATITUDE: -61.759500 * EAST-BOUND LONGITUDE: -55.409700 * DATE/TIME START: 2001-03-02T00:00:00 * DATE/TIME END: 2001-03-07T00:00:00 2004 application/zip, 2 datasets https://doi.pangaea.de/10.1594/PANGAEA.847724 https://doi.org/10.1594/PANGAEA.847724 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.847724 https://doi.org/10.1594/PANGAEA.847724 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess Supplement to: Fretzdorff, Susanne; Worthington, Tim J; Haase, Karsten M; Hekinian, Roger; Franz, Leander; Keller, Randall A; Stoffers, Peter (2004): Magmatism in the Bransfield Basin: Rifting of the South Shetland Arc? Journal of Geophysical Research, 109(B12), https://doi.org/10.1029/2004JB003046 Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas SPP1158 dataset publication series 2004 ftpangaea https://doi.org/10.1594/PANGAEA.84772410.1029/2004JB003046 2024-07-24T02:31:21Z Bransfield Basin is an actively extending marginal basin separating the inactive South Shetland arc from the northern Antarctic Peninsula. Rift-related volcanism is widespread throughout the central Bransfield Basin, but the wider eastern Bransfield Basin was previously unsampled. Lavas recovered from the eastern subbasin form three distinct groups: (1) Bransfield Group has moderate large-ion lithophile element (LILE) enrichment relative to normal mid-ocean ridge basalt (NMORB), (2) Gibbs Group has strong LILE enrichment and is restricted to a relic seamount interpreted as part of the South Shetland arc, and (3) fresh alkali basalt was recovered from the NE part of the basin near Spanish Rise. The subduction-related component in Bransfield and Gibbs Group lavas is a LILE-rich fluid with radiogenic Sr, Nd, and Pb isotope compositions derived predominantly from subducting sediment. These lavas can be modeled as melts from Pacific MORB source mantle contaminated by up to 5% of the subduction-related component. They further reveal that Pacific mantle, rather than South Atlantic mantle, has underlain Bransfield Basin since 3 Ma. Magma productivity decreases abruptly east of Bridgeman Rise, and lavas with the least subduction component outcrop at that end. Both the eastward decrease in subduction component and occurrence of young alkali basalts require that subduction-modified mantle generated during the lifetime of the South Shetland arc has been progressively removed from NE to SW. This is inconsistent with previous models suggesting continued slow subduction at the South Shetland Trench but instead favors models in which the South Scotia Ridge fault has propagated westward since 3 Ma generating transtension across the basin. Other/Unknown Material Antarc* Antarctic Antarctic Peninsula Sea ice PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(-57.277700,-55.409700,-61.759500,-62.192300) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas SPP1158 |
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Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas SPP1158 Fretzdorff, Susanne Worthington, Tim J Haase, Karsten M Hekinian, Roger Franz, Leander Keller, Randall A Stoffers, Peter Geochemical and isotopic composition of Bransfield Basin Lavas collected during SONNE cruise SO155 |
topic_facet |
Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas SPP1158 |
description |
Bransfield Basin is an actively extending marginal basin separating the inactive South Shetland arc from the northern Antarctic Peninsula. Rift-related volcanism is widespread throughout the central Bransfield Basin, but the wider eastern Bransfield Basin was previously unsampled. Lavas recovered from the eastern subbasin form three distinct groups: (1) Bransfield Group has moderate large-ion lithophile element (LILE) enrichment relative to normal mid-ocean ridge basalt (NMORB), (2) Gibbs Group has strong LILE enrichment and is restricted to a relic seamount interpreted as part of the South Shetland arc, and (3) fresh alkali basalt was recovered from the NE part of the basin near Spanish Rise. The subduction-related component in Bransfield and Gibbs Group lavas is a LILE-rich fluid with radiogenic Sr, Nd, and Pb isotope compositions derived predominantly from subducting sediment. These lavas can be modeled as melts from Pacific MORB source mantle contaminated by up to 5% of the subduction-related component. They further reveal that Pacific mantle, rather than South Atlantic mantle, has underlain Bransfield Basin since 3 Ma. Magma productivity decreases abruptly east of Bridgeman Rise, and lavas with the least subduction component outcrop at that end. Both the eastward decrease in subduction component and occurrence of young alkali basalts require that subduction-modified mantle generated during the lifetime of the South Shetland arc has been progressively removed from NE to SW. This is inconsistent with previous models suggesting continued slow subduction at the South Shetland Trench but instead favors models in which the South Scotia Ridge fault has propagated westward since 3 Ma generating transtension across the basin. |
format |
Other/Unknown Material |
author |
Fretzdorff, Susanne Worthington, Tim J Haase, Karsten M Hekinian, Roger Franz, Leander Keller, Randall A Stoffers, Peter |
author_facet |
Fretzdorff, Susanne Worthington, Tim J Haase, Karsten M Hekinian, Roger Franz, Leander Keller, Randall A Stoffers, Peter |
author_sort |
Fretzdorff, Susanne |
title |
Geochemical and isotopic composition of Bransfield Basin Lavas collected during SONNE cruise SO155 |
title_short |
Geochemical and isotopic composition of Bransfield Basin Lavas collected during SONNE cruise SO155 |
title_full |
Geochemical and isotopic composition of Bransfield Basin Lavas collected during SONNE cruise SO155 |
title_fullStr |
Geochemical and isotopic composition of Bransfield Basin Lavas collected during SONNE cruise SO155 |
title_full_unstemmed |
Geochemical and isotopic composition of Bransfield Basin Lavas collected during SONNE cruise SO155 |
title_sort |
geochemical and isotopic composition of bransfield basin lavas collected during sonne cruise so155 |
publisher |
PANGAEA |
publishDate |
2004 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.847724 https://doi.org/10.1594/PANGAEA.847724 |
op_coverage |
MEDIAN LATITUDE: -61.979642 * MEDIAN LONGITUDE: -56.328732 * SOUTH-BOUND LATITUDE: -62.192300 * WEST-BOUND LONGITUDE: -57.277700 * NORTH-BOUND LATITUDE: -61.759500 * EAST-BOUND LONGITUDE: -55.409700 * DATE/TIME START: 2001-03-02T00:00:00 * DATE/TIME END: 2001-03-07T00:00:00 |
long_lat |
ENVELOPE(-57.277700,-55.409700,-61.759500,-62.192300) |
genre |
Antarc* Antarctic Antarctic Peninsula Sea ice |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Sea ice |
op_source |
Supplement to: Fretzdorff, Susanne; Worthington, Tim J; Haase, Karsten M; Hekinian, Roger; Franz, Leander; Keller, Randall A; Stoffers, Peter (2004): Magmatism in the Bransfield Basin: Rifting of the South Shetland Arc? Journal of Geophysical Research, 109(B12), https://doi.org/10.1029/2004JB003046 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.847724 https://doi.org/10.1594/PANGAEA.847724 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1594/PANGAEA.84772410.1029/2004JB003046 |
_version_ |
1810488651494195200 |