Transcontinental retroarc sediment routing controlled by subduction geometry and climate change (Central and Southern Andes, Argentina)
AbstractCentral Argentina from the Pampean flat‐slab segment to northern Patagonia (27°–41°S) represents a classic example of a broken retroarc basin with strong tectonic and climatic control on fluvial sediment transport. Combined with previous research focused on coastal sediments, this actualisti...
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ftopenaccessrep:oai:zenodo.org:103603 2023-10-25T01:39:37+02:00 Transcontinental retroarc sediment routing controlled by subduction geometry and climate change (Central and Southern Andes, Argentina) Mara Limonta Eduardo Garzanti Giovanni Vezzoli Tomas N. Capaldi Numa Sosa 2021-09-08 https://www.openaccessrepository.it/record/103603 https://doi.org/10.1111/bre.12607 eng eng url:https://www.openaccessrepository.it/communities/itmirror https://www.openaccessrepository.it/record/103603 doi:10.1111/bre.12607 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/ NEANIAS Atmospheric Research Community Geology info:eu-repo/semantics/article publication-article 2021 ftopenaccessrep https://doi.org/10.1111/bre.12607 2023-09-26T22:18:37Z AbstractCentral Argentina from the Pampean flat‐slab segment to northern Patagonia (27°–41°S) represents a classic example of a broken retroarc basin with strong tectonic and climatic control on fluvial sediment transport. Combined with previous research focused on coastal sediments, this actualistic provenance study uses framework petrography and heavy‐mineral data to trace multistep dispersal of volcaniclastic detritus first eastwards across central Argentina for up to ca. 1,500 km and next northwards for another 760 km along the Atlantic coast. Although detritus generated in the Andes is largely derived from mesosilicic volcanic rocks of the cordillera, its compositional signatures reflect different tectono‐stratigraphic levels of the orogen uplifted along strike in response to varying subduction geometry as well as different character and crystallization condition of arc magmas through time and space. River sand, thus, changes from feldspatho‐litho‐quartzose or litho‐feldspatho‐quartzose in the north, where sedimentary detritus is more common, to mostly quartzo‐feldspatho‐lithic in the centre and to feldspatho‐lithic in the south, where volcanic detritus is dominant. The transparent‐heavy‐mineral suite changes markedly from amphibole ≫ clinopyroxene > orthopyroxene in the north, to amphibole ≈ clinopyroxene ≈ orthopyroxene in the centre and to orthopyroxene ≥ clinopyroxene ≫ amphibole in the south. In the presently dry climate, fluvial discharge is drastically reduced to the point that even the Desaguadero trunk river has become endorheic and orogenic detritus is dumped in the retroarc basin, reworked by winds and temporarily accumulated in dune fields. During the Quaternary, instead, much larger amounts of water were released by melting of the Cordilleran ice sheet or during pluvial events. The sediment‐laden waters of the Desaguadero and Colorado rivers then rushed from the tract of the Andes with greatest topographic and structural elevation, fostering alluvial fans inland and flowing in much larger ... Article in Journal/Newspaper Ice Sheet Istituto Nazionale di Fisica Nucleare (INFN): Open Access Repository Argentina Patagonia Basin Research 33 6 3406 3437 |
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Open Polar |
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Istituto Nazionale di Fisica Nucleare (INFN): Open Access Repository |
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ftopenaccessrep |
language |
English |
topic |
NEANIAS Atmospheric Research Community Geology |
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NEANIAS Atmospheric Research Community Geology Mara Limonta Eduardo Garzanti Giovanni Vezzoli Tomas N. Capaldi Numa Sosa Transcontinental retroarc sediment routing controlled by subduction geometry and climate change (Central and Southern Andes, Argentina) |
topic_facet |
NEANIAS Atmospheric Research Community Geology |
description |
AbstractCentral Argentina from the Pampean flat‐slab segment to northern Patagonia (27°–41°S) represents a classic example of a broken retroarc basin with strong tectonic and climatic control on fluvial sediment transport. Combined with previous research focused on coastal sediments, this actualistic provenance study uses framework petrography and heavy‐mineral data to trace multistep dispersal of volcaniclastic detritus first eastwards across central Argentina for up to ca. 1,500 km and next northwards for another 760 km along the Atlantic coast. Although detritus generated in the Andes is largely derived from mesosilicic volcanic rocks of the cordillera, its compositional signatures reflect different tectono‐stratigraphic levels of the orogen uplifted along strike in response to varying subduction geometry as well as different character and crystallization condition of arc magmas through time and space. River sand, thus, changes from feldspatho‐litho‐quartzose or litho‐feldspatho‐quartzose in the north, where sedimentary detritus is more common, to mostly quartzo‐feldspatho‐lithic in the centre and to feldspatho‐lithic in the south, where volcanic detritus is dominant. The transparent‐heavy‐mineral suite changes markedly from amphibole ≫ clinopyroxene > orthopyroxene in the north, to amphibole ≈ clinopyroxene ≈ orthopyroxene in the centre and to orthopyroxene ≥ clinopyroxene ≫ amphibole in the south. In the presently dry climate, fluvial discharge is drastically reduced to the point that even the Desaguadero trunk river has become endorheic and orogenic detritus is dumped in the retroarc basin, reworked by winds and temporarily accumulated in dune fields. During the Quaternary, instead, much larger amounts of water were released by melting of the Cordilleran ice sheet or during pluvial events. The sediment‐laden waters of the Desaguadero and Colorado rivers then rushed from the tract of the Andes with greatest topographic and structural elevation, fostering alluvial fans inland and flowing in much larger ... |
format |
Article in Journal/Newspaper |
author |
Mara Limonta Eduardo Garzanti Giovanni Vezzoli Tomas N. Capaldi Numa Sosa |
author_facet |
Mara Limonta Eduardo Garzanti Giovanni Vezzoli Tomas N. Capaldi Numa Sosa |
author_sort |
Mara Limonta |
title |
Transcontinental retroarc sediment routing controlled by subduction geometry and climate change (Central and Southern Andes, Argentina) |
title_short |
Transcontinental retroarc sediment routing controlled by subduction geometry and climate change (Central and Southern Andes, Argentina) |
title_full |
Transcontinental retroarc sediment routing controlled by subduction geometry and climate change (Central and Southern Andes, Argentina) |
title_fullStr |
Transcontinental retroarc sediment routing controlled by subduction geometry and climate change (Central and Southern Andes, Argentina) |
title_full_unstemmed |
Transcontinental retroarc sediment routing controlled by subduction geometry and climate change (Central and Southern Andes, Argentina) |
title_sort |
transcontinental retroarc sediment routing controlled by subduction geometry and climate change (central and southern andes, argentina) |
publishDate |
2021 |
url |
https://www.openaccessrepository.it/record/103603 https://doi.org/10.1111/bre.12607 |
geographic |
Argentina Patagonia |
geographic_facet |
Argentina Patagonia |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_relation |
url:https://www.openaccessrepository.it/communities/itmirror https://www.openaccessrepository.it/record/103603 doi:10.1111/bre.12607 |
op_rights |
info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1111/bre.12607 |
container_title |
Basin Research |
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33 |
container_issue |
6 |
container_start_page |
3406 |
op_container_end_page |
3437 |
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1780734951280345088 |