The Armorican Massif (Western France) - A buried relief two times exhumed in response to Iberia-Eurasia movements (Early Cretaceous, base of Cenozoic)
International audience The Armorican Massif is an outcropping Variscan basement located in Western France. The age of its exhumation is debated, as most of the outcropping European basements: Is this relief a remnant of the planation of the Variscan Belt or a buried and then exhumed relief at time o...
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HAL CCSD
2014
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Online Access: | https://insu.hal.science/insu-00975782 |
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Institut national des sciences de l'Univers: HAL-INSU |
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language |
English |
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[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
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[SDU.STU]Sciences of the Universe [physics]/Earth Sciences Bessin, Paul Guillocheau, François Robin, Cécile Bauer, Hugues Schroetter, Jean Michel The Armorican Massif (Western France) - A buried relief two times exhumed in response to Iberia-Eurasia movements (Early Cretaceous, base of Cenozoic) |
topic_facet |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience The Armorican Massif is an outcropping Variscan basement located in Western France. The age of its exhumation is debated, as most of the outcropping European basements: Is this relief a remnant of the planation of the Variscan Belt or a buried and then exhumed relief at time of the North-Atlantic (Biscay Bay) opening during Early Cretaceous or/and during the Africa-Eurasia convergence? We performed a geomorphological study (based on DEM analysis and field controls) of the different landforms of the Armorican Massif. The dating of those relief forms is based on their geometrical relationships with the weatherings and dated preserved sediments. Our results allow to propose a model of evolution of the Armorican Massif and of its relief for the Mesozoic to Cenozoic period and underscore four main points: (1) The Armorican relief preserved old landforms - planation surfaces (mainly pediments and pediplains) - of Triassic (?) to Early Cretaceous age buried by Jurassic and Upper Cretaceous (chalk) carbonate platforms. (2) Those paleo-landforms were exhumed at two periods (i) Early Cretaceous in response to the opening of the Biscay Bay and (ii) Upermost Cretaceous-Paleocene at time of the Iberia-Eurasia increasing of convergence. (3) A major planation surface - called the Armorican Surface - result from the Early Cretaceous physical and chemical (laterite) erosion when the Armorican Massif was the North rift shoulder of the Biscay Bay. This planation surface is later deformed (buckling?) and eroded during Uppermost Cretaceous and Paleocene. (4) During Paleogene times, a last generation of pediments is shaped and then flooded by the Mid-Miocene eustatic sea-level rise. (5) The Armorican relief and landforms is later incised by rivers, (i) during Upper Miocene to Pliocene and (ii) at the Early to Middle Pleistocene transition with the incision of the present-day valleys in both response to uplift (Apulia-Eurasia convergence) and climate (precipitation) change. |
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) Dyanmique des Bassins 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)-Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR) Bureau de Recherches Géologiques et Minières (BRGM) (BRGM) |
format |
Conference Object |
author |
Bessin, Paul Guillocheau, François Robin, Cécile Bauer, Hugues Schroetter, Jean Michel |
author_facet |
Bessin, Paul Guillocheau, François Robin, Cécile Bauer, Hugues Schroetter, Jean Michel |
author_sort |
Bessin, Paul |
title |
The Armorican Massif (Western France) - A buried relief two times exhumed in response to Iberia-Eurasia movements (Early Cretaceous, base of Cenozoic) |
title_short |
The Armorican Massif (Western France) - A buried relief two times exhumed in response to Iberia-Eurasia movements (Early Cretaceous, base of Cenozoic) |
title_full |
The Armorican Massif (Western France) - A buried relief two times exhumed in response to Iberia-Eurasia movements (Early Cretaceous, base of Cenozoic) |
title_fullStr |
The Armorican Massif (Western France) - A buried relief two times exhumed in response to Iberia-Eurasia movements (Early Cretaceous, base of Cenozoic) |
title_full_unstemmed |
The Armorican Massif (Western France) - A buried relief two times exhumed in response to Iberia-Eurasia movements (Early Cretaceous, base of Cenozoic) |
title_sort |
armorican massif (western france) - a buried relief two times exhumed in response to iberia-eurasia movements (early cretaceous, base of cenozoic) |
publisher |
HAL CCSD |
publishDate |
2014 |
url |
https://insu.hal.science/insu-00975782 |
op_coverage |
Vienne, Austria |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
EGU General Assembly 2014 https://insu.hal.science/insu-00975782 EGU General Assembly 2014, Apr 2014, Vienne, Austria. 16, pp.EGU2014-5310-1, 2014 |
op_relation |
insu-00975782 https://insu.hal.science/insu-00975782 |
_version_ |
1790604672846790656 |
spelling |
ftinsu:oai:HAL:insu-00975782v1 2024-02-11T10:06:45+01:00 The Armorican Massif (Western France) - A buried relief two times exhumed in response to Iberia-Eurasia movements (Early Cretaceous, base of Cenozoic) Bessin, Paul Guillocheau, François Robin, Cécile Bauer, Hugues Schroetter, Jean Michel 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) Dyanmique des Bassins 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)-Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR) Bureau de Recherches Géologiques et Minières (BRGM) (BRGM) Vienne, Austria 2014-04-27 https://insu.hal.science/insu-00975782 en eng HAL CCSD insu-00975782 https://insu.hal.science/insu-00975782 EGU General Assembly 2014 https://insu.hal.science/insu-00975782 EGU General Assembly 2014, Apr 2014, Vienne, Austria. 16, pp.EGU2014-5310-1, 2014 [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/conferenceObject Conference poster 2014 ftinsu 2024-01-24T17:22:23Z International audience The Armorican Massif is an outcropping Variscan basement located in Western France. The age of its exhumation is debated, as most of the outcropping European basements: Is this relief a remnant of the planation of the Variscan Belt or a buried and then exhumed relief at time of the North-Atlantic (Biscay Bay) opening during Early Cretaceous or/and during the Africa-Eurasia convergence? We performed a geomorphological study (based on DEM analysis and field controls) of the different landforms of the Armorican Massif. The dating of those relief forms is based on their geometrical relationships with the weatherings and dated preserved sediments. Our results allow to propose a model of evolution of the Armorican Massif and of its relief for the Mesozoic to Cenozoic period and underscore four main points: (1) The Armorican relief preserved old landforms - planation surfaces (mainly pediments and pediplains) - of Triassic (?) to Early Cretaceous age buried by Jurassic and Upper Cretaceous (chalk) carbonate platforms. (2) Those paleo-landforms were exhumed at two periods (i) Early Cretaceous in response to the opening of the Biscay Bay and (ii) Upermost Cretaceous-Paleocene at time of the Iberia-Eurasia increasing of convergence. (3) A major planation surface - called the Armorican Surface - result from the Early Cretaceous physical and chemical (laterite) erosion when the Armorican Massif was the North rift shoulder of the Biscay Bay. This planation surface is later deformed (buckling?) and eroded during Uppermost Cretaceous and Paleocene. (4) During Paleogene times, a last generation of pediments is shaped and then flooded by the Mid-Miocene eustatic sea-level rise. (5) The Armorican relief and landforms is later incised by rivers, (i) during Upper Miocene to Pliocene and (ii) at the Early to Middle Pleistocene transition with the incision of the present-day valleys in both response to uplift (Apulia-Eurasia convergence) and climate (precipitation) change. Conference Object North Atlantic Institut national des sciences de l'Univers: HAL-INSU |