Structure and activity of the geothermal field of Hvalfjörour (Iceland) from brittle tectonic, geothermal and paleostress analysis
International audience This paper presents the results of brittle tectonic, palaeostress inversion, and hydrothermal mineralisation studies of the Hvalfjörður low-temperature geothermal field in Southwest Iceland. This geothermal field (including two pronounced thermal anomalies) is located in the h...
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ftunivnantes:oai:HAL:hal-01452861v1 2023-05-15T16:47:17+02:00 Structure and activity of the geothermal field of Hvalfjörour (Iceland) from brittle tectonic, geothermal and paleostress analysis Bergerat, Françoise Saemundsson, Kristjan Fourel, Loïc Angelier, Jacques Institut des Sciences de la Terre de Paris (iSTeP) Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS) Iceland GeoSurvey (ISOR ) Géoazur (GEOAZUR 6526) Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS) COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS) 2013 https://hal.archives-ouvertes.fr/hal-01452861 https://doi.org/10.2113/gssgfbull.184.4-5.451 en eng HAL CCSD Société géologique de France info:eu-repo/semantics/altIdentifier/doi/10.2113/gssgfbull.184.4-5.451 hal-01452861 https://hal.archives-ouvertes.fr/hal-01452861 doi:10.2113/gssgfbull.184.4-5.451 ISSN: 0037-9409 EISSN: 1777-5817 Bulletin de la Société Géologique de France https://hal.archives-ouvertes.fr/hal-01452861 Bulletin de la Société Géologique de France, Société géologique de France, 2013, 184 (4-5), pp.451-465. ⟨10.2113/gssgfbull.184.4-5.451⟩ [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2013 ftunivnantes https://doi.org/10.2113/gssgfbull.184.4-5.451 2022-08-10T07:08:42Z International audience This paper presents the results of brittle tectonic, palaeostress inversion, and hydrothermal mineralisation studies of the Hvalfjörður low-temperature geothermal field in Southwest Iceland. This geothermal field (including two pronounced thermal anomalies) is located in the highly altered core area of an extinct and deeply eroded Tertiary central volcano. Most of the geothermal water appears to be conducted by vertical extension fractures. Palaeostress analysis indicates a rather complex stress history, with four major trends of extension involving normal and strike-slip faulting modes as well as dyke injection. Analysis of the data on the relative chronology indicates that these four regimes were closely intricate in time and space. The most important regime is a NW-SE, rift-perpendicular extension related to the oceanic rifting in Iceland. This trend partly controls the past (Pliocene-Early Pleistocene) hydrothermal activity in the Hvalfjörður area; however, an E-W rift-oblique extension also occurred with a N-S trending fracture system including normal faults, dykes and veins that show higher levels of hydrothermal mineralisation. Currently, there is strong hot-water convection, producing a thermal anomaly, in this N-S-trending fracture system. Our study highlights the paleostress evolution and the development of fracture systems in Hvalfjörður, including the past geothermal history; nevertheless the most efficient tool in geothermal prospection in such complex area remains the shallow geothermal survey. It has proved successful in many localities in Early Pleistocene to Miocene rocks where no surface indication of geothermal activity exists. Article in Journal/Newspaper Iceland Université de Nantes: HAL-UNIV-NANTES Hvalfjörður ENVELOPE(-21.663,-21.663,64.376,64.376) Bulletin de la Société Géologique de France 184 4-5 451 465 |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences Bergerat, Françoise Saemundsson, Kristjan Fourel, Loïc Angelier, Jacques Structure and activity of the geothermal field of Hvalfjörour (Iceland) from brittle tectonic, geothermal and paleostress analysis |
topic_facet |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience This paper presents the results of brittle tectonic, palaeostress inversion, and hydrothermal mineralisation studies of the Hvalfjörður low-temperature geothermal field in Southwest Iceland. This geothermal field (including two pronounced thermal anomalies) is located in the highly altered core area of an extinct and deeply eroded Tertiary central volcano. Most of the geothermal water appears to be conducted by vertical extension fractures. Palaeostress analysis indicates a rather complex stress history, with four major trends of extension involving normal and strike-slip faulting modes as well as dyke injection. Analysis of the data on the relative chronology indicates that these four regimes were closely intricate in time and space. The most important regime is a NW-SE, rift-perpendicular extension related to the oceanic rifting in Iceland. This trend partly controls the past (Pliocene-Early Pleistocene) hydrothermal activity in the Hvalfjörður area; however, an E-W rift-oblique extension also occurred with a N-S trending fracture system including normal faults, dykes and veins that show higher levels of hydrothermal mineralisation. Currently, there is strong hot-water convection, producing a thermal anomaly, in this N-S-trending fracture system. Our study highlights the paleostress evolution and the development of fracture systems in Hvalfjörður, including the past geothermal history; nevertheless the most efficient tool in geothermal prospection in such complex area remains the shallow geothermal survey. It has proved successful in many localities in Early Pleistocene to Miocene rocks where no surface indication of geothermal activity exists. |
author2 |
Institut des Sciences de la Terre de Paris (iSTeP) Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS) Iceland GeoSurvey (ISOR ) Géoazur (GEOAZUR 6526) Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS) COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Bergerat, Françoise Saemundsson, Kristjan Fourel, Loïc Angelier, Jacques |
author_facet |
Bergerat, Françoise Saemundsson, Kristjan Fourel, Loïc Angelier, Jacques |
author_sort |
Bergerat, Françoise |
title |
Structure and activity of the geothermal field of Hvalfjörour (Iceland) from brittle tectonic, geothermal and paleostress analysis |
title_short |
Structure and activity of the geothermal field of Hvalfjörour (Iceland) from brittle tectonic, geothermal and paleostress analysis |
title_full |
Structure and activity of the geothermal field of Hvalfjörour (Iceland) from brittle tectonic, geothermal and paleostress analysis |
title_fullStr |
Structure and activity of the geothermal field of Hvalfjörour (Iceland) from brittle tectonic, geothermal and paleostress analysis |
title_full_unstemmed |
Structure and activity of the geothermal field of Hvalfjörour (Iceland) from brittle tectonic, geothermal and paleostress analysis |
title_sort |
structure and activity of the geothermal field of hvalfjörour (iceland) from brittle tectonic, geothermal and paleostress analysis |
publisher |
HAL CCSD |
publishDate |
2013 |
url |
https://hal.archives-ouvertes.fr/hal-01452861 https://doi.org/10.2113/gssgfbull.184.4-5.451 |
long_lat |
ENVELOPE(-21.663,-21.663,64.376,64.376) |
geographic |
Hvalfjörður |
geographic_facet |
Hvalfjörður |
genre |
Iceland |
genre_facet |
Iceland |
op_source |
ISSN: 0037-9409 EISSN: 1777-5817 Bulletin de la Société Géologique de France https://hal.archives-ouvertes.fr/hal-01452861 Bulletin de la Société Géologique de France, Société géologique de France, 2013, 184 (4-5), pp.451-465. ⟨10.2113/gssgfbull.184.4-5.451⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.2113/gssgfbull.184.4-5.451 hal-01452861 https://hal.archives-ouvertes.fr/hal-01452861 doi:10.2113/gssgfbull.184.4-5.451 |
op_doi |
https://doi.org/10.2113/gssgfbull.184.4-5.451 |
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Bulletin de la Société Géologique de France |
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184 |
container_issue |
4-5 |
container_start_page |
451 |
op_container_end_page |
465 |
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