The geochemical and mineralogical fingerprint of West Antarctica’s weak underbelly: Pine Island and Thwaites glaciers
The marine-based West Antarctic Ice Sheet (WAIS) is considered the most unstable part of the Antarctic Ice Sheet, with particular vulnerability in the Amundsen Sea sector where glaciers are melting at an alarming rate. Far-field sea-level data and ice-sheet models have pointed towards at least one m...
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ftimperialcol:oai:spiral.imperial.ac.uk:10044/1/79847 2023-05-15T13:23:57+02:00 The geochemical and mineralogical fingerprint of West Antarctica’s weak underbelly: Pine Island and Thwaites glaciers Simoes Pereira, P Van de Flierdt, T Hemming, SR Frederichs, T Hammond, SJ Brachfeld, S Doherty, C Kuhn, G Smith, JA Klages, JP Hillenbrand, C-D 2020-04-27 http://hdl.handle.net/10044/1/79847 https://doi.org/10.1016/j.chemgeo.2020.119649 unknown Elsevier Chemical Geology 0009-2541 http://hdl.handle.net/10044/1/79847 doi:10.1016/j.chemgeo.2020.119649 © 2020 Elsevier B.V. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/ CC-BY-NC-ND Geochemistry & Geophysics 0402 Geochemistry 0403 Geology 0406 Physical Geography and Environmental Geoscience Journal Article 2020 ftimperialcol https://doi.org/10.1016/j.chemgeo.2020.119649 2021-05-06T22:39:23Z The marine-based West Antarctic Ice Sheet (WAIS) is considered the most unstable part of the Antarctic Ice Sheet, with particular vulnerability in the Amundsen Sea sector where glaciers are melting at an alarming rate. Far-field sea-level data and ice-sheet models have pointed towards at least one major WAIS disintegration during the Late Quaternary, but direct evidence for past collapse(s) from ice-proximal geological archives remains elusive. In order to facilitate geochemical and mineralogical tracing of the two most important glaciers draining into the Amundsen Sea, i.e. Pine Island Glacier (PIG) and Thwaites Glacier (TG), we here provide the first multi-proxy provenance analysis of 26 seafloor surface sediment samples from Pine Island Bay. Our data show that the fingerprints of detritus delivered by PIG and TG are clearly distinct near the ice-shelf fronts of both ice-stream systems for all grain sizes and proxies investigated. Glacial detritus delivered by PIG is characterised by low εNd values (~−9), high 87Sr/86Sr ratios (~0.728), low smectite content (<10%), and hornblende and biotite grains with Late Permian to Jurassic (170–270 Ma) cooling ages. In contrast, glacigenic detritus delivered by TG is characterised by higher εNd values (~−4), lower 87Sr/86Sr ratios (0.714), higher smectite (20%) and kaolinite content (37%), biotite and hornblende grains with 40Ar/39Ar cooling ages of <40 Ma and ~115 Ma, and high content of mafic minerals. The geochemical and mineralogical fingerprints for PIG and TG reported here provide novel insights into sub-ice geology and allow us to trace both drainage systems in the geological past, under environmental conditions more similar to those envisioned in the next 50 to 100 years. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Ice Sheet Ice Shelf Pine Island Bay Pine Island Glacier Thwaites Glacier Imperial College London: Spiral Amundsen Sea Antarctic Island Bay ENVELOPE(-109.085,-109.085,59.534,59.534) Pine Island Bay ENVELOPE(-102.000,-102.000,-74.750,-74.750) Pine Island Glacier ENVELOPE(-101.000,-101.000,-75.000,-75.000) The Antarctic Thwaites Glacier ENVELOPE(-106.750,-106.750,-75.500,-75.500) West Antarctic Ice Sheet Chemical Geology 550 119649 |
institution |
Open Polar |
collection |
Imperial College London: Spiral |
op_collection_id |
ftimperialcol |
language |
unknown |
topic |
Geochemistry & Geophysics 0402 Geochemistry 0403 Geology 0406 Physical Geography and Environmental Geoscience |
spellingShingle |
Geochemistry & Geophysics 0402 Geochemistry 0403 Geology 0406 Physical Geography and Environmental Geoscience Simoes Pereira, P Van de Flierdt, T Hemming, SR Frederichs, T Hammond, SJ Brachfeld, S Doherty, C Kuhn, G Smith, JA Klages, JP Hillenbrand, C-D The geochemical and mineralogical fingerprint of West Antarctica’s weak underbelly: Pine Island and Thwaites glaciers |
topic_facet |
Geochemistry & Geophysics 0402 Geochemistry 0403 Geology 0406 Physical Geography and Environmental Geoscience |
description |
The marine-based West Antarctic Ice Sheet (WAIS) is considered the most unstable part of the Antarctic Ice Sheet, with particular vulnerability in the Amundsen Sea sector where glaciers are melting at an alarming rate. Far-field sea-level data and ice-sheet models have pointed towards at least one major WAIS disintegration during the Late Quaternary, but direct evidence for past collapse(s) from ice-proximal geological archives remains elusive. In order to facilitate geochemical and mineralogical tracing of the two most important glaciers draining into the Amundsen Sea, i.e. Pine Island Glacier (PIG) and Thwaites Glacier (TG), we here provide the first multi-proxy provenance analysis of 26 seafloor surface sediment samples from Pine Island Bay. Our data show that the fingerprints of detritus delivered by PIG and TG are clearly distinct near the ice-shelf fronts of both ice-stream systems for all grain sizes and proxies investigated. Glacial detritus delivered by PIG is characterised by low εNd values (~−9), high 87Sr/86Sr ratios (~0.728), low smectite content (<10%), and hornblende and biotite grains with Late Permian to Jurassic (170–270 Ma) cooling ages. In contrast, glacigenic detritus delivered by TG is characterised by higher εNd values (~−4), lower 87Sr/86Sr ratios (0.714), higher smectite (20%) and kaolinite content (37%), biotite and hornblende grains with 40Ar/39Ar cooling ages of <40 Ma and ~115 Ma, and high content of mafic minerals. The geochemical and mineralogical fingerprints for PIG and TG reported here provide novel insights into sub-ice geology and allow us to trace both drainage systems in the geological past, under environmental conditions more similar to those envisioned in the next 50 to 100 years. |
format |
Article in Journal/Newspaper |
author |
Simoes Pereira, P Van de Flierdt, T Hemming, SR Frederichs, T Hammond, SJ Brachfeld, S Doherty, C Kuhn, G Smith, JA Klages, JP Hillenbrand, C-D |
author_facet |
Simoes Pereira, P Van de Flierdt, T Hemming, SR Frederichs, T Hammond, SJ Brachfeld, S Doherty, C Kuhn, G Smith, JA Klages, JP Hillenbrand, C-D |
author_sort |
Simoes Pereira, P |
title |
The geochemical and mineralogical fingerprint of West Antarctica’s weak underbelly: Pine Island and Thwaites glaciers |
title_short |
The geochemical and mineralogical fingerprint of West Antarctica’s weak underbelly: Pine Island and Thwaites glaciers |
title_full |
The geochemical and mineralogical fingerprint of West Antarctica’s weak underbelly: Pine Island and Thwaites glaciers |
title_fullStr |
The geochemical and mineralogical fingerprint of West Antarctica’s weak underbelly: Pine Island and Thwaites glaciers |
title_full_unstemmed |
The geochemical and mineralogical fingerprint of West Antarctica’s weak underbelly: Pine Island and Thwaites glaciers |
title_sort |
geochemical and mineralogical fingerprint of west antarctica’s weak underbelly: pine island and thwaites glaciers |
publisher |
Elsevier |
publishDate |
2020 |
url |
http://hdl.handle.net/10044/1/79847 https://doi.org/10.1016/j.chemgeo.2020.119649 |
long_lat |
ENVELOPE(-109.085,-109.085,59.534,59.534) ENVELOPE(-102.000,-102.000,-74.750,-74.750) ENVELOPE(-101.000,-101.000,-75.000,-75.000) ENVELOPE(-106.750,-106.750,-75.500,-75.500) |
geographic |
Amundsen Sea Antarctic Island Bay Pine Island Bay Pine Island Glacier The Antarctic Thwaites Glacier West Antarctic Ice Sheet |
geographic_facet |
Amundsen Sea Antarctic Island Bay Pine Island Bay Pine Island Glacier The Antarctic Thwaites Glacier West Antarctic Ice Sheet |
genre |
Amundsen Sea Antarc* Antarctic Ice Sheet Ice Shelf Pine Island Bay Pine Island Glacier Thwaites Glacier |
genre_facet |
Amundsen Sea Antarc* Antarctic Ice Sheet Ice Shelf Pine Island Bay Pine Island Glacier Thwaites Glacier |
op_relation |
Chemical Geology 0009-2541 http://hdl.handle.net/10044/1/79847 doi:10.1016/j.chemgeo.2020.119649 |
op_rights |
© 2020 Elsevier B.V. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.1016/j.chemgeo.2020.119649 |
container_title |
Chemical Geology |
container_volume |
550 |
container_start_page |
119649 |
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1766376549985026048 |