Connecting the Aracuai and Ribeira belts (SE - Brazil): Progressive transition from contractional to transpressive strain regime during the Brasiliano orogeny
International audience Whether the Araçuaí and the Ribeira Neoproterozoic belts in southeast Brazil represent a continuous or two distinct orogenic belts is still a debated question. We compile existing geologic and geophysical data and argue that the two belts, in spite of differences in tectonic s...
Published in: | Journal of South American Earth Sciences |
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Online Access: | https://hal.science/hal-01934487 https://doi.org/10.1016/j.jsames.2018.06.005 |
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ftunimontpellier:oai:HAL:hal-01934487v1 2024-04-28T08:20:25+00:00 Connecting the Aracuai and Ribeira belts (SE - Brazil): Progressive transition from contractional to transpressive strain regime during the Brasiliano orogeny Egydio-Silva, Marcos Vauchez, Alain Fossen, Haakon Goncalves Cavalcante, Geane Carolina Xavier, Bruna Catarino Universidade de São Paulo Géosciences Montpellier Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA) University of Bergen (UiB) Universidade Federal do Paraná Curitiba, Brasil = Federal University of Paraná Curitiba, Brazil = Université fédérale du Paraná Curitiba, Brésil (UFPR) 2018-10 https://hal.science/hal-01934487 https://doi.org/10.1016/j.jsames.2018.06.005 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jsames.2018.06.005 hal-01934487 https://hal.science/hal-01934487 doi:10.1016/j.jsames.2018.06.005 ISSN: 0895-9811 EISSN: 1873-0647 Journal of South American Earth Sciences https://hal.science/hal-01934487 Journal of South American Earth Sciences, 2018, 86, pp.127-139. ⟨10.1016/j.jsames.2018.06.005⟩ Ribeira belt Aracuai orogen Transcurrent shear zone Transpression Collisional tectonics West gondwana [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics info:eu-repo/semantics/article Journal articles 2018 ftunimontpellier https://doi.org/10.1016/j.jsames.2018.06.005 2024-04-10T14:37:26Z International audience Whether the Araçuaí and the Ribeira Neoproterozoic belts in southeast Brazil represent a continuous or two distinct orogenic belts is still a debated question. We compile existing geologic and geophysical data and argue that the two belts, in spite of differences in tectonic style and kinematics, should be considered as part of an orogenic continuity that formed during the mostly Late Proterozoic Brasiliano orogenic evolution. Structural mapping supported by Anisotropy of Magnetic Susceptibility data shows that the transition between the two belts is gradual, with a progressive change from a NE-trending subvertical foliation and subhorizontal stretching lineation in the Ribeira belt to gently dipping and less pronounced fabrics in the Araçuaí belt. The lineation progressively changes northward from NE to E-W, suggesting a transition from overall transcurrent to thrust kinematics, and the solid-state finite strain seems to get progressively higher into the Ribeira belt. Differences in tectonic style are explained by the southward termination of the rigid São Francisco craton, which caused oblique collision and lateral escape, as supported by numerical modeling. Shear-wave splitting measurements suggest that the transcurrent deformation in the Ribeira belt affected the entire lithosphere. In the transitional zone, the seismic anisotropy pattern is more complex and the delay time between the fast and slow shear-waves is smaller. These observations, together with a similar record of magmatism and timing of orogenic events and P-T conditions during peak metamorphism strongly support continuity between the Araçuaí and the Ribeira belts. This model is a "quasi-facsimile" of the Paleoproterozoic deformation that occurred in the Great Slave Lake area in Canada. Article in Journal/Newspaper Great Slave Lake Université de Montpellier: HAL Journal of South American Earth Sciences 86 127 139 |
institution |
Open Polar |
collection |
Université de Montpellier: HAL |
op_collection_id |
ftunimontpellier |
language |
English |
topic |
Ribeira belt Aracuai orogen Transcurrent shear zone Transpression Collisional tectonics West gondwana [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics |
spellingShingle |
Ribeira belt Aracuai orogen Transcurrent shear zone Transpression Collisional tectonics West gondwana [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics Egydio-Silva, Marcos Vauchez, Alain Fossen, Haakon Goncalves Cavalcante, Geane Carolina Xavier, Bruna Catarino Connecting the Aracuai and Ribeira belts (SE - Brazil): Progressive transition from contractional to transpressive strain regime during the Brasiliano orogeny |
topic_facet |
Ribeira belt Aracuai orogen Transcurrent shear zone Transpression Collisional tectonics West gondwana [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics |
description |
International audience Whether the Araçuaí and the Ribeira Neoproterozoic belts in southeast Brazil represent a continuous or two distinct orogenic belts is still a debated question. We compile existing geologic and geophysical data and argue that the two belts, in spite of differences in tectonic style and kinematics, should be considered as part of an orogenic continuity that formed during the mostly Late Proterozoic Brasiliano orogenic evolution. Structural mapping supported by Anisotropy of Magnetic Susceptibility data shows that the transition between the two belts is gradual, with a progressive change from a NE-trending subvertical foliation and subhorizontal stretching lineation in the Ribeira belt to gently dipping and less pronounced fabrics in the Araçuaí belt. The lineation progressively changes northward from NE to E-W, suggesting a transition from overall transcurrent to thrust kinematics, and the solid-state finite strain seems to get progressively higher into the Ribeira belt. Differences in tectonic style are explained by the southward termination of the rigid São Francisco craton, which caused oblique collision and lateral escape, as supported by numerical modeling. Shear-wave splitting measurements suggest that the transcurrent deformation in the Ribeira belt affected the entire lithosphere. In the transitional zone, the seismic anisotropy pattern is more complex and the delay time between the fast and slow shear-waves is smaller. These observations, together with a similar record of magmatism and timing of orogenic events and P-T conditions during peak metamorphism strongly support continuity between the Araçuaí and the Ribeira belts. This model is a "quasi-facsimile" of the Paleoproterozoic deformation that occurred in the Great Slave Lake area in Canada. |
author2 |
Universidade de São Paulo Géosciences Montpellier Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA) University of Bergen (UiB) Universidade Federal do Paraná Curitiba, Brasil = Federal University of Paraná Curitiba, Brazil = Université fédérale du Paraná Curitiba, Brésil (UFPR) |
format |
Article in Journal/Newspaper |
author |
Egydio-Silva, Marcos Vauchez, Alain Fossen, Haakon Goncalves Cavalcante, Geane Carolina Xavier, Bruna Catarino |
author_facet |
Egydio-Silva, Marcos Vauchez, Alain Fossen, Haakon Goncalves Cavalcante, Geane Carolina Xavier, Bruna Catarino |
author_sort |
Egydio-Silva, Marcos |
title |
Connecting the Aracuai and Ribeira belts (SE - Brazil): Progressive transition from contractional to transpressive strain regime during the Brasiliano orogeny |
title_short |
Connecting the Aracuai and Ribeira belts (SE - Brazil): Progressive transition from contractional to transpressive strain regime during the Brasiliano orogeny |
title_full |
Connecting the Aracuai and Ribeira belts (SE - Brazil): Progressive transition from contractional to transpressive strain regime during the Brasiliano orogeny |
title_fullStr |
Connecting the Aracuai and Ribeira belts (SE - Brazil): Progressive transition from contractional to transpressive strain regime during the Brasiliano orogeny |
title_full_unstemmed |
Connecting the Aracuai and Ribeira belts (SE - Brazil): Progressive transition from contractional to transpressive strain regime during the Brasiliano orogeny |
title_sort |
connecting the aracuai and ribeira belts (se - brazil): progressive transition from contractional to transpressive strain regime during the brasiliano orogeny |
publisher |
HAL CCSD |
publishDate |
2018 |
url |
https://hal.science/hal-01934487 https://doi.org/10.1016/j.jsames.2018.06.005 |
genre |
Great Slave Lake |
genre_facet |
Great Slave Lake |
op_source |
ISSN: 0895-9811 EISSN: 1873-0647 Journal of South American Earth Sciences https://hal.science/hal-01934487 Journal of South American Earth Sciences, 2018, 86, pp.127-139. ⟨10.1016/j.jsames.2018.06.005⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jsames.2018.06.005 hal-01934487 https://hal.science/hal-01934487 doi:10.1016/j.jsames.2018.06.005 |
op_doi |
https://doi.org/10.1016/j.jsames.2018.06.005 |
container_title |
Journal of South American Earth Sciences |
container_volume |
86 |
container_start_page |
127 |
op_container_end_page |
139 |
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1797583340463718400 |