Regional mid-Pleistocene glaciation in central Patagonia
Southern South America contains a glacial geomorphological record that spans the past million years and has the potential to provide palaeoclimate information for several glacial periods in Earth's history. In central Patagonia, two major outlet glaciers of the former Patagonian Ice Sheet carve...
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ftubkoeln:oai:USBKOELN.ub.uni-koeln.de:23117 2023-05-15T16:41:16+02:00 Regional mid-Pleistocene glaciation in central Patagonia Hein, Andrew S. Cogez, Antoine Darvill, Christopher M. Mendelova, Monika Kaplan, Michael R. Herman, Frederic Dunai, Tibor J. Norton, Kevin Xu, Sheng Christl, Marcus Rodes, Angel 2017 https://kups.ub.uni-koeln.de/23117/ eng eng PERGAMON-ELSEVIER SCIENCE LTD Hein, Andrew S., Cogez, Antoine, Darvill, Christopher M., Mendelova, Monika, Kaplan, Michael R., Herman, Frederic orcid:0000-0002-7237-4656 , Dunai, Tibor J., Norton, Kevin orcid:0000-0002-7995-6464 , Xu, Sheng, Christl, Marcus orcid:0000-0002-3131-6652 and Rodes, Angel orcid:0000-0001-8488-7689 (2017). Regional mid-Pleistocene glaciation in central Patagonia. Quat. Sci. Rev., 164. S. 77 - 95. OXFORD: PERGAMON-ELSEVIER SCIENCE LTD. ISSN 0277-3791 ddc:no doc-type:article publishedVersion 2017 ftubkoeln 2022-11-09T07:19:06Z Southern South America contains a glacial geomorphological record that spans the past million years and has the potential to provide palaeoclimate information for several glacial periods in Earth's history. In central Patagonia, two major outlet glaciers of the former Patagonian Ice Sheet carved deep basins similar to 50 km wide and extending over 100 km into the Andean plain east of the mountain front. A succession of nested glacial moraines offers the possibility of determining when the ice lobes advanced and whether such advances occurred synchronously. The existing chronology, which was obtained using different methods in each valley, indicates the penultimate moraines differ in age by a full glacial cycle. Here, we test this hypothesis further using a uniform methodology that combines cosmogenic nuclide ages from moraine boulders, moraine cobbles and outwash cobbles. Be-10 concentrations in eighteen outwash cobbles from the Moreno outwash terrace in the Lago Buenos Aires valley yield surface exposure ages of 169-269 ka. We find Be-10 inheritance is low and therefore use the oldest surface cobbles to date the deposit at 260-270 ka, which is indistinguishable from the age obtained in the neighbouring Lago Pueyrredon valley. This suggests a regionally significant glaciation during Marine Isotope Stage 8, and broad interhemispheric synchrony of glacial maxima during the mid to late Pleistocene. Finally, we find the dated outwash terrace is 70-100 ka older than the associated moraines. On the basis of geomorphological observations, we suggest this difference can be explained by exhumation of moraine boulders. (C) 2017 Elsevier Ltd. All rights reserved. Article in Journal/Newspaper Ice Sheet Cologne University: KUPS Moreno ENVELOPE(-62.300,-62.300,-64.083,-64.083) Patagonia |
institution |
Open Polar |
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Cologne University: KUPS |
op_collection_id |
ftubkoeln |
language |
English |
topic |
ddc:no |
spellingShingle |
ddc:no Hein, Andrew S. Cogez, Antoine Darvill, Christopher M. Mendelova, Monika Kaplan, Michael R. Herman, Frederic Dunai, Tibor J. Norton, Kevin Xu, Sheng Christl, Marcus Rodes, Angel Regional mid-Pleistocene glaciation in central Patagonia |
topic_facet |
ddc:no |
description |
Southern South America contains a glacial geomorphological record that spans the past million years and has the potential to provide palaeoclimate information for several glacial periods in Earth's history. In central Patagonia, two major outlet glaciers of the former Patagonian Ice Sheet carved deep basins similar to 50 km wide and extending over 100 km into the Andean plain east of the mountain front. A succession of nested glacial moraines offers the possibility of determining when the ice lobes advanced and whether such advances occurred synchronously. The existing chronology, which was obtained using different methods in each valley, indicates the penultimate moraines differ in age by a full glacial cycle. Here, we test this hypothesis further using a uniform methodology that combines cosmogenic nuclide ages from moraine boulders, moraine cobbles and outwash cobbles. Be-10 concentrations in eighteen outwash cobbles from the Moreno outwash terrace in the Lago Buenos Aires valley yield surface exposure ages of 169-269 ka. We find Be-10 inheritance is low and therefore use the oldest surface cobbles to date the deposit at 260-270 ka, which is indistinguishable from the age obtained in the neighbouring Lago Pueyrredon valley. This suggests a regionally significant glaciation during Marine Isotope Stage 8, and broad interhemispheric synchrony of glacial maxima during the mid to late Pleistocene. Finally, we find the dated outwash terrace is 70-100 ka older than the associated moraines. On the basis of geomorphological observations, we suggest this difference can be explained by exhumation of moraine boulders. (C) 2017 Elsevier Ltd. All rights reserved. |
format |
Article in Journal/Newspaper |
author |
Hein, Andrew S. Cogez, Antoine Darvill, Christopher M. Mendelova, Monika Kaplan, Michael R. Herman, Frederic Dunai, Tibor J. Norton, Kevin Xu, Sheng Christl, Marcus Rodes, Angel |
author_facet |
Hein, Andrew S. Cogez, Antoine Darvill, Christopher M. Mendelova, Monika Kaplan, Michael R. Herman, Frederic Dunai, Tibor J. Norton, Kevin Xu, Sheng Christl, Marcus Rodes, Angel |
author_sort |
Hein, Andrew S. |
title |
Regional mid-Pleistocene glaciation in central Patagonia |
title_short |
Regional mid-Pleistocene glaciation in central Patagonia |
title_full |
Regional mid-Pleistocene glaciation in central Patagonia |
title_fullStr |
Regional mid-Pleistocene glaciation in central Patagonia |
title_full_unstemmed |
Regional mid-Pleistocene glaciation in central Patagonia |
title_sort |
regional mid-pleistocene glaciation in central patagonia |
publisher |
PERGAMON-ELSEVIER SCIENCE LTD |
publishDate |
2017 |
url |
https://kups.ub.uni-koeln.de/23117/ |
long_lat |
ENVELOPE(-62.300,-62.300,-64.083,-64.083) |
geographic |
Moreno Patagonia |
geographic_facet |
Moreno Patagonia |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_relation |
Hein, Andrew S., Cogez, Antoine, Darvill, Christopher M., Mendelova, Monika, Kaplan, Michael R., Herman, Frederic orcid:0000-0002-7237-4656 , Dunai, Tibor J., Norton, Kevin orcid:0000-0002-7995-6464 , Xu, Sheng, Christl, Marcus orcid:0000-0002-3131-6652 and Rodes, Angel orcid:0000-0001-8488-7689 (2017). Regional mid-Pleistocene glaciation in central Patagonia. Quat. Sci. Rev., 164. S. 77 - 95. OXFORD: PERGAMON-ELSEVIER SCIENCE LTD. ISSN 0277-3791 |
_version_ |
1766031700152811520 |