Geochemical fingerprints of glacially eroded bedrock from West Antarctica: detrital thermochronology, radiogenic isotope systematics and trace element geochemistry in Late Holocene glacial-marine sediments.
Geochemical provenance studies of glacial-marine sediments provide a powerful approach to describe subglacial geology, sediment transport pathways, and past ice sheet dynamics. The marine-based West Antarctic Ice Sheet (WAIS) is considered highly vulnerable to ocean warming and sea level rise that i...
Published in: | Earth-Science Reviews |
---|---|
Main Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
Elsevier
2018
|
Subjects: | |
Online Access: | http://hdl.handle.net/10044/1/59340 https://doi.org/10.1016/j.earscirev.2018.04.011 |
id |
ftimperialcol:oai:spiral.imperial.ac.uk:10044/1/59340 |
---|---|
record_format |
openpolar |
institution |
Open Polar |
collection |
Imperial College London: Spiral |
op_collection_id |
ftimperialcol |
language |
unknown |
topic |
04 Earth Sciences Geology |
spellingShingle |
04 Earth Sciences Geology Simoes Pereira, P Van de Flierdt, T Hemming, SR Hammond, SJ Kuhn, G Brachfeld, S Doherty, C Hillenbrand, CD Geochemical fingerprints of glacially eroded bedrock from West Antarctica: detrital thermochronology, radiogenic isotope systematics and trace element geochemistry in Late Holocene glacial-marine sediments. |
topic_facet |
04 Earth Sciences Geology |
description |
Geochemical provenance studies of glacial-marine sediments provide a powerful approach to describe subglacial geology, sediment transport pathways, and past ice sheet dynamics. The marine-based West Antarctic Ice Sheet (WAIS) is considered highly vulnerable to ocean warming and sea level rise that is likely to cause its rapid and irreversible retreat. Studies of its past response to climate change are hence essential for projecting its future behaviour. The application of radiogenic and trace element provenance studies for past ice sheet reconstructions requires surveying the geographic variability of geochemical compositions of glaciomarine sediments. In this study, we characterize the provenance of the detrital fraction of 67 Late Holocene marine sediment samples collected off the Pacific margin of West Antarctica (60°W to 160°W), including 40Ar/39Ar ages of individual hornblende and biotite grains (>150 μm), as well as Sr and Nd isotope and trace element composition of the fine-grained (<63 μm) sediment fraction. Overall, this approach allows differentiating West Antarctica into five source regions: the Antarctic Peninsula, Bellingshausen Sea, Amundsen Sea, Wrigley Gulf-Hobbs Coast and Sulzberger Bay. Minor geochemical variability is found within each individual sector due to local variability in onland geology. 40Ar/39Ar ages of iceberg-rafted hornblende and biotite grains record primarily Carboniferous to Lates Quaternary ages (~0 to 380 Ma), with a notable age peak of ~100 Ma, associated with plutonic intrusions or deformation events during the mid-Cretaceous. Permian-Jurassic 40Ar/39Ar ages are widespread in the Amundsen Sea sector, marking episodes of large-volume magmatism along the long-lived continental margin. Metasedimentary rocks and Late Cenozoic alkali basalts in West Antarctica cannot be detected using detrital hornblende and biotite 40Ar/39Ar ages due to the absence or small grain-size (i.e. <150 μm) of these minerals in such rocks. These sources can however be readily recognized by their fine-grained geochemical composition. In addition, geographic trends in the provenance from proximal to distal sites provide insights into major sediment transport pathways. While the transport of fine-grained detritus follows bathymetric cross-shelf troughs, the distribution of iceberg-rafted grains shows influence by transport in the Antarctic Coastal Current. Our study provides the first systematic geochemical characterisation of sediment provenance off West Antarctica, and highlights the importance of combining multiple provenance approaches in different size fractions of glacial-marine sediments, and paves the way to investigate past WAIS dynamics. |
format |
Article in Journal/Newspaper |
author |
Simoes Pereira, P Van de Flierdt, T Hemming, SR Hammond, SJ Kuhn, G Brachfeld, S Doherty, C Hillenbrand, CD |
author_facet |
Simoes Pereira, P Van de Flierdt, T Hemming, SR Hammond, SJ Kuhn, G Brachfeld, S Doherty, C Hillenbrand, CD |
author_sort |
Simoes Pereira, P |
title |
Geochemical fingerprints of glacially eroded bedrock from West Antarctica: detrital thermochronology, radiogenic isotope systematics and trace element geochemistry in Late Holocene glacial-marine sediments. |
title_short |
Geochemical fingerprints of glacially eroded bedrock from West Antarctica: detrital thermochronology, radiogenic isotope systematics and trace element geochemistry in Late Holocene glacial-marine sediments. |
title_full |
Geochemical fingerprints of glacially eroded bedrock from West Antarctica: detrital thermochronology, radiogenic isotope systematics and trace element geochemistry in Late Holocene glacial-marine sediments. |
title_fullStr |
Geochemical fingerprints of glacially eroded bedrock from West Antarctica: detrital thermochronology, radiogenic isotope systematics and trace element geochemistry in Late Holocene glacial-marine sediments. |
title_full_unstemmed |
Geochemical fingerprints of glacially eroded bedrock from West Antarctica: detrital thermochronology, radiogenic isotope systematics and trace element geochemistry in Late Holocene glacial-marine sediments. |
title_sort |
geochemical fingerprints of glacially eroded bedrock from west antarctica: detrital thermochronology, radiogenic isotope systematics and trace element geochemistry in late holocene glacial-marine sediments. |
publisher |
Elsevier |
publishDate |
2018 |
url |
http://hdl.handle.net/10044/1/59340 https://doi.org/10.1016/j.earscirev.2018.04.011 |
long_lat |
ENVELOPE(-57.500,-57.500,-64.300,-64.300) ENVELOPE(-136.000,-136.000,-75.500,-75.500) ENVELOPE(-152.000,-152.000,-77.000,-77.000) ENVELOPE(-123.354,-123.354,63.194,63.194) ENVELOPE(-128.000,-128.000,-73.750,-73.750) |
geographic |
Amundsen Sea Antarctic Antarctic Peninsula Bellingshausen Sea Hobbs Hobbs Coast Pacific Sulzberger Bay The Antarctic West Antarctic Ice Sheet West Antarctica Wrigley Wrigley Gulf |
geographic_facet |
Amundsen Sea Antarctic Antarctic Peninsula Bellingshausen Sea Hobbs Hobbs Coast Pacific Sulzberger Bay The Antarctic West Antarctic Ice Sheet West Antarctica Wrigley Wrigley Gulf |
genre |
Amundsen Sea Antarc* Antarctic Antarctic Peninsula Antarctica Bellingshausen Sea Hobbs coast Ice Sheet Iceberg* Sulzberger Bay West Antarctica |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctic Peninsula Antarctica Bellingshausen Sea Hobbs coast Ice Sheet Iceberg* Sulzberger Bay West Antarctica |
op_source |
232 204 |
op_relation |
Earth-Science Reviews |
op_rights |
© 2018 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.1016/j.earscirev.2018.04.011 |
container_title |
Earth-Science Reviews |
container_volume |
182 |
container_start_page |
204 |
op_container_end_page |
232 |
_version_ |
1766377270997417984 |
spelling |
ftimperialcol:oai:spiral.imperial.ac.uk:10044/1/59340 2023-05-15T13:24:04+02:00 Geochemical fingerprints of glacially eroded bedrock from West Antarctica: detrital thermochronology, radiogenic isotope systematics and trace element geochemistry in Late Holocene glacial-marine sediments. Simoes Pereira, P Van de Flierdt, T Hemming, SR Hammond, SJ Kuhn, G Brachfeld, S Doherty, C Hillenbrand, CD 2018-04-30 http://hdl.handle.net/10044/1/59340 https://doi.org/10.1016/j.earscirev.2018.04.011 unknown Elsevier Earth-Science Reviews © 2018 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ CC-BY-NC-ND 232 204 04 Earth Sciences Geology Journal Article 2018 ftimperialcol https://doi.org/10.1016/j.earscirev.2018.04.011 2019-05-09T22:40:15Z Geochemical provenance studies of glacial-marine sediments provide a powerful approach to describe subglacial geology, sediment transport pathways, and past ice sheet dynamics. The marine-based West Antarctic Ice Sheet (WAIS) is considered highly vulnerable to ocean warming and sea level rise that is likely to cause its rapid and irreversible retreat. Studies of its past response to climate change are hence essential for projecting its future behaviour. The application of radiogenic and trace element provenance studies for past ice sheet reconstructions requires surveying the geographic variability of geochemical compositions of glaciomarine sediments. In this study, we characterize the provenance of the detrital fraction of 67 Late Holocene marine sediment samples collected off the Pacific margin of West Antarctica (60°W to 160°W), including 40Ar/39Ar ages of individual hornblende and biotite grains (>150 μm), as well as Sr and Nd isotope and trace element composition of the fine-grained (<63 μm) sediment fraction. Overall, this approach allows differentiating West Antarctica into five source regions: the Antarctic Peninsula, Bellingshausen Sea, Amundsen Sea, Wrigley Gulf-Hobbs Coast and Sulzberger Bay. Minor geochemical variability is found within each individual sector due to local variability in onland geology. 40Ar/39Ar ages of iceberg-rafted hornblende and biotite grains record primarily Carboniferous to Lates Quaternary ages (~0 to 380 Ma), with a notable age peak of ~100 Ma, associated with plutonic intrusions or deformation events during the mid-Cretaceous. Permian-Jurassic 40Ar/39Ar ages are widespread in the Amundsen Sea sector, marking episodes of large-volume magmatism along the long-lived continental margin. Metasedimentary rocks and Late Cenozoic alkali basalts in West Antarctica cannot be detected using detrital hornblende and biotite 40Ar/39Ar ages due to the absence or small grain-size (i.e. <150 μm) of these minerals in such rocks. These sources can however be readily recognized by their fine-grained geochemical composition. In addition, geographic trends in the provenance from proximal to distal sites provide insights into major sediment transport pathways. While the transport of fine-grained detritus follows bathymetric cross-shelf troughs, the distribution of iceberg-rafted grains shows influence by transport in the Antarctic Coastal Current. Our study provides the first systematic geochemical characterisation of sediment provenance off West Antarctica, and highlights the importance of combining multiple provenance approaches in different size fractions of glacial-marine sediments, and paves the way to investigate past WAIS dynamics. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Antarctic Peninsula Antarctica Bellingshausen Sea Hobbs coast Ice Sheet Iceberg* Sulzberger Bay West Antarctica Imperial College London: Spiral Amundsen Sea Antarctic Antarctic Peninsula Bellingshausen Sea Hobbs ENVELOPE(-57.500,-57.500,-64.300,-64.300) Hobbs Coast ENVELOPE(-136.000,-136.000,-75.500,-75.500) Pacific Sulzberger Bay ENVELOPE(-152.000,-152.000,-77.000,-77.000) The Antarctic West Antarctic Ice Sheet West Antarctica Wrigley ENVELOPE(-123.354,-123.354,63.194,63.194) Wrigley Gulf ENVELOPE(-128.000,-128.000,-73.750,-73.750) Earth-Science Reviews 182 204 232 |