Shortening of Archaean and Paleoproterozoic continental lithospheres: large strains, but no orogeny
International audience In many ancient deformation belts of Archaean and Paleoproterozoic age (e.g. Terre Adélie in East Antarctica, Finnish Svecofennides in Southern Finland, Murchison Belt in South Africa, Thompson Nickel Belt in Manitoba, Dharwar Craton in western India, Abitibi sub-Province in Q...
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ftbrgm:oai:HAL:insu-02539543v1 2024-05-19T07:32:37+00:00 Shortening of Archaean and Paleoproterozoic continental lithospheres: large strains, but no orogeny Gapais, Denis Poh, Jonathan Yamato, Philippe Duretz, Thibault Cagnard, Florence Géosciences Rennes (GR) Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR) Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS) Bureau de Recherches Géologiques et Minières (BRGM) online, Austria 2020-04-04 https://insu.hal.science/insu-02539543 https://insu.hal.science/insu-02539543/document https://insu.hal.science/insu-02539543/file/gapais-EGU2020.pdf en eng HAL CCSD insu-02539543 https://insu.hal.science/insu-02539543 https://insu.hal.science/insu-02539543/document https://insu.hal.science/insu-02539543/file/gapais-EGU2020.pdf info:eu-repo/semantics/OpenAccess European Geosciences Union General Assembly https://insu.hal.science/insu-02539543 European Geosciences Union General Assembly, Apr 2020, online, Austria. pp.EGU2020-1496 [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics info:eu-repo/semantics/conferenceObject Conference papers 2020 ftbrgm 2024-05-02T00:14:15Z International audience In many ancient deformation belts of Archaean and Paleoproterozoic age (e.g. Terre Adélie in East Antarctica, Finnish Svecofennides in Southern Finland, Murchison Belt in South Africa, Thompson Nickel Belt in Manitoba, Dharwar Craton in western India, Abitibi sub-Province in Québec, Trans-Hudson belt of Canada, Trans-Amazonian belt of Suriname), latest recorded deformations are compressive or transpressive. In these belts that involved hot and weak continental crusts, deformations are distributed with basically vertical tectonics and important crustal thickening. On the other hand, there is no evidence of syn-orogenic extension or late-orogenic collapse, as classically observed in modern orogens where extensional detachments are widespread.Analogue and numerical models emphasize that shortening of weak and hot lithospheres basically favour downward motions, which result in limited topographies. Field evidence further point to metamorphic isogrades rather parallel to the Earth surface at belt scale. Hence, metamorphic conditions are rather monotonous at the scale of individual belts, with limited metamorphic jumps and typical P-T paths with no significant adiabatic retrograde segments. Consistently, localized deep detrital sedimentary basins like foreland or intra-mountain basins, are not documented. Sedimentary records rather suggest distributed sedimentation processes. In addition, several lines of evidence tend to point out that cooling of ancient hot deformation belts was rather slow, which is consistent with distributed topographies and long-lasting erosion-driven exhumation processes. On these bases, we propose that gravity-driven collapse had no reason to occur in ancient hot deformation belts because important topographic gradients and orogeny could not develop as observed in modern mountain chains. Conference Object Antarc* Antarctica East Antarctica BRGM: HAL (Bureau de Recherches Géologiques et Minières) |
institution |
Open Polar |
collection |
BRGM: HAL (Bureau de Recherches Géologiques et Minières) |
op_collection_id |
ftbrgm |
language |
English |
topic |
[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics |
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[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics Gapais, Denis Poh, Jonathan Yamato, Philippe Duretz, Thibault Cagnard, Florence Shortening of Archaean and Paleoproterozoic continental lithospheres: large strains, but no orogeny |
topic_facet |
[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics |
description |
International audience In many ancient deformation belts of Archaean and Paleoproterozoic age (e.g. Terre Adélie in East Antarctica, Finnish Svecofennides in Southern Finland, Murchison Belt in South Africa, Thompson Nickel Belt in Manitoba, Dharwar Craton in western India, Abitibi sub-Province in Québec, Trans-Hudson belt of Canada, Trans-Amazonian belt of Suriname), latest recorded deformations are compressive or transpressive. In these belts that involved hot and weak continental crusts, deformations are distributed with basically vertical tectonics and important crustal thickening. On the other hand, there is no evidence of syn-orogenic extension or late-orogenic collapse, as classically observed in modern orogens where extensional detachments are widespread.Analogue and numerical models emphasize that shortening of weak and hot lithospheres basically favour downward motions, which result in limited topographies. Field evidence further point to metamorphic isogrades rather parallel to the Earth surface at belt scale. Hence, metamorphic conditions are rather monotonous at the scale of individual belts, with limited metamorphic jumps and typical P-T paths with no significant adiabatic retrograde segments. Consistently, localized deep detrital sedimentary basins like foreland or intra-mountain basins, are not documented. Sedimentary records rather suggest distributed sedimentation processes. In addition, several lines of evidence tend to point out that cooling of ancient hot deformation belts was rather slow, which is consistent with distributed topographies and long-lasting erosion-driven exhumation processes. On these bases, we propose that gravity-driven collapse had no reason to occur in ancient hot deformation belts because important topographic gradients and orogeny could not develop as observed in modern mountain chains. |
author2 |
Géosciences Rennes (GR) Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR) Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS) Bureau de Recherches Géologiques et Minières (BRGM) |
format |
Conference Object |
author |
Gapais, Denis Poh, Jonathan Yamato, Philippe Duretz, Thibault Cagnard, Florence |
author_facet |
Gapais, Denis Poh, Jonathan Yamato, Philippe Duretz, Thibault Cagnard, Florence |
author_sort |
Gapais, Denis |
title |
Shortening of Archaean and Paleoproterozoic continental lithospheres: large strains, but no orogeny |
title_short |
Shortening of Archaean and Paleoproterozoic continental lithospheres: large strains, but no orogeny |
title_full |
Shortening of Archaean and Paleoproterozoic continental lithospheres: large strains, but no orogeny |
title_fullStr |
Shortening of Archaean and Paleoproterozoic continental lithospheres: large strains, but no orogeny |
title_full_unstemmed |
Shortening of Archaean and Paleoproterozoic continental lithospheres: large strains, but no orogeny |
title_sort |
shortening of archaean and paleoproterozoic continental lithospheres: large strains, but no orogeny |
publisher |
HAL CCSD |
publishDate |
2020 |
url |
https://insu.hal.science/insu-02539543 https://insu.hal.science/insu-02539543/document https://insu.hal.science/insu-02539543/file/gapais-EGU2020.pdf |
op_coverage |
online, Austria |
genre |
Antarc* Antarctica East Antarctica |
genre_facet |
Antarc* Antarctica East Antarctica |
op_source |
European Geosciences Union General Assembly https://insu.hal.science/insu-02539543 European Geosciences Union General Assembly, Apr 2020, online, Austria. pp.EGU2020-1496 |
op_relation |
insu-02539543 https://insu.hal.science/insu-02539543 https://insu.hal.science/insu-02539543/document https://insu.hal.science/insu-02539543/file/gapais-EGU2020.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1799470725712576512 |