Deep structure of the Armorican Basin (Bay of Biscay): a review of Norgasis seismic reflection and refraction data
International audience The Bay of Biscay is bounded to the North by the North Biscay margin, which comprises the Western Approaches and Armorican segments. In the 1970s and 1980s, most researchers considered this margin typical of a non-volcanic passive margin: It is characterized by a striking succ...
Published in: | Journal of the Geological Society |
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Online Access: | https://brgm.hal.science/hal-00647845 https://brgm.hal.science/hal-00647845/document https://brgm.hal.science/hal-00647845/file/Thinon_SGL_2003_draft.pdf https://doi.org/10.1144/0016-764901-103 |
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ftbrgm:oai:HAL:hal-00647845v1 2024-05-19T07:45:11+00:00 Deep structure of the Armorican Basin (Bay of Biscay): a review of Norgasis seismic reflection and refraction data Thinon, Isabelle Matias, Luis Réhault, Jean-Pierre Hirn, Alfred Fidalgo-González, Luis Avedik, Félix Bureau de Recherches Géologiques et Minières (BRGM) Faculdade de Ciencias Universidade de Lisboa = University of Lisbon (ULISBOA) Domaines Océaniques (LDO) Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS) Institut de Physique du Globe de Paris (IPGP) Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS) 2003-01-31 https://brgm.hal.science/hal-00647845 https://brgm.hal.science/hal-00647845/document https://brgm.hal.science/hal-00647845/file/Thinon_SGL_2003_draft.pdf https://doi.org/10.1144/0016-764901-103 en eng HAL CCSD Geological Society of London info:eu-repo/semantics/altIdentifier/doi/10.1144/0016-764901-103 hal-00647845 https://brgm.hal.science/hal-00647845 https://brgm.hal.science/hal-00647845/document https://brgm.hal.science/hal-00647845/file/Thinon_SGL_2003_draft.pdf doi:10.1144/0016-764901-103 info:eu-repo/semantics/OpenAccess Journal of the Geological Society of London https://brgm.hal.science/hal-00647845 Journal of the Geological Society of London, 2003, 160, pp.99-116. ⟨10.1144/0016-764901-103⟩ Bay of Biscay passive margins transition zones rifting crustal thinning OCEAN-CONTINENT BOUNDARY CRUSTAL STRUCTURE NORTH-ATLANTIC [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2003 ftbrgm https://doi.org/10.1144/0016-764901-103 2024-05-02T00:03:00Z International audience The Bay of Biscay is bounded to the North by the North Biscay margin, which comprises the Western Approaches and Armorican segments. In the 1970s and 1980s, most researchers considered this margin typical of a non-volcanic passive margin: It is characterized by a striking succession of tilted blocks beneath which occurs the S reflector and the continent/ocean boundary is abrupt. This paper examines the Armorican segment and is based on a study of all early seismic profiles together with new multichannel reflection and refraction seismic data (NORGASIS cruise). An important result is the discovery of a 80-km wide Ocean-Continent Transition zone that coincides with the Armorican Basin (a deep sedimentary basin). It is characterized by a High-Velocity Layer-Crust (7.4-7.5 km/s) overlain by sediments. The other results are: i) the main crustal thinning occurs exclusively under the narrow continental slope. ii) The tilted blocks and the S-reflector are observed only at the base of the continental slope in the narrow domain called "neck area". iii) the North Biscay Ridge is a large oceanic plateau present only off the NW Armorican margin rather than a long ridge elongated off the whole North Biscay Margin. Article in Journal/Newspaper North Atlantic BRGM: HAL (Bureau de Recherches Géologiques et Minières) Journal of the Geological Society 160 1 99 116 |
institution |
Open Polar |
collection |
BRGM: HAL (Bureau de Recherches Géologiques et Minières) |
op_collection_id |
ftbrgm |
language |
English |
topic |
Bay of Biscay passive margins transition zones rifting crustal thinning OCEAN-CONTINENT BOUNDARY CRUSTAL STRUCTURE NORTH-ATLANTIC [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
Bay of Biscay passive margins transition zones rifting crustal thinning OCEAN-CONTINENT BOUNDARY CRUSTAL STRUCTURE NORTH-ATLANTIC [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Thinon, Isabelle Matias, Luis Réhault, Jean-Pierre Hirn, Alfred Fidalgo-González, Luis Avedik, Félix Deep structure of the Armorican Basin (Bay of Biscay): a review of Norgasis seismic reflection and refraction data |
topic_facet |
Bay of Biscay passive margins transition zones rifting crustal thinning OCEAN-CONTINENT BOUNDARY CRUSTAL STRUCTURE NORTH-ATLANTIC [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience The Bay of Biscay is bounded to the North by the North Biscay margin, which comprises the Western Approaches and Armorican segments. In the 1970s and 1980s, most researchers considered this margin typical of a non-volcanic passive margin: It is characterized by a striking succession of tilted blocks beneath which occurs the S reflector and the continent/ocean boundary is abrupt. This paper examines the Armorican segment and is based on a study of all early seismic profiles together with new multichannel reflection and refraction seismic data (NORGASIS cruise). An important result is the discovery of a 80-km wide Ocean-Continent Transition zone that coincides with the Armorican Basin (a deep sedimentary basin). It is characterized by a High-Velocity Layer-Crust (7.4-7.5 km/s) overlain by sediments. The other results are: i) the main crustal thinning occurs exclusively under the narrow continental slope. ii) The tilted blocks and the S-reflector are observed only at the base of the continental slope in the narrow domain called "neck area". iii) the North Biscay Ridge is a large oceanic plateau present only off the NW Armorican margin rather than a long ridge elongated off the whole North Biscay Margin. |
author2 |
Bureau de Recherches Géologiques et Minières (BRGM) Faculdade de Ciencias Universidade de Lisboa = University of Lisbon (ULISBOA) Domaines Océaniques (LDO) Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS) Institut de Physique du Globe de Paris (IPGP) Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Thinon, Isabelle Matias, Luis Réhault, Jean-Pierre Hirn, Alfred Fidalgo-González, Luis Avedik, Félix |
author_facet |
Thinon, Isabelle Matias, Luis Réhault, Jean-Pierre Hirn, Alfred Fidalgo-González, Luis Avedik, Félix |
author_sort |
Thinon, Isabelle |
title |
Deep structure of the Armorican Basin (Bay of Biscay): a review of Norgasis seismic reflection and refraction data |
title_short |
Deep structure of the Armorican Basin (Bay of Biscay): a review of Norgasis seismic reflection and refraction data |
title_full |
Deep structure of the Armorican Basin (Bay of Biscay): a review of Norgasis seismic reflection and refraction data |
title_fullStr |
Deep structure of the Armorican Basin (Bay of Biscay): a review of Norgasis seismic reflection and refraction data |
title_full_unstemmed |
Deep structure of the Armorican Basin (Bay of Biscay): a review of Norgasis seismic reflection and refraction data |
title_sort |
deep structure of the armorican basin (bay of biscay): a review of norgasis seismic reflection and refraction data |
publisher |
HAL CCSD |
publishDate |
2003 |
url |
https://brgm.hal.science/hal-00647845 https://brgm.hal.science/hal-00647845/document https://brgm.hal.science/hal-00647845/file/Thinon_SGL_2003_draft.pdf https://doi.org/10.1144/0016-764901-103 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Journal of the Geological Society of London https://brgm.hal.science/hal-00647845 Journal of the Geological Society of London, 2003, 160, pp.99-116. ⟨10.1144/0016-764901-103⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1144/0016-764901-103 hal-00647845 https://brgm.hal.science/hal-00647845 https://brgm.hal.science/hal-00647845/document https://brgm.hal.science/hal-00647845/file/Thinon_SGL_2003_draft.pdf doi:10.1144/0016-764901-103 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1144/0016-764901-103 |
container_title |
Journal of the Geological Society |
container_volume |
160 |
container_issue |
1 |
container_start_page |
99 |
op_container_end_page |
116 |
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1799485145482264576 |