New aspects and perspectives on tsavorite deposits
International audience Tsavorite, the vanadian variety of green grossular, is a high value economic gemstone. It is hosted exclusively in the metasedimentary formations from the Neoproterozoic Metamorphic Mozambique Belt. The deposits are mined in Kenya, Tanzania and Madagascar and other occurrences...
Published in: | Ore Geology Reviews |
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Main Authors: | , , , , , , , , , , , , , , , , , , , , |
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Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2013
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Online Access: | https://hal.archives-ouvertes.fr/hal-00853279 https://doi.org/10.1016/j.oregeorev.2013.01.016 |
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ftccsdartic:oai:HAL:hal-00853279v1 |
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Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
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ftccsdartic |
language |
English |
topic |
Genetic model Metasomatism Evaporites Neoproterozoic Metamorphic Mozambique Belt Tsavorite Graphitic gneiss [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography |
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Genetic model Metasomatism Evaporites Neoproterozoic Metamorphic Mozambique Belt Tsavorite Graphitic gneiss [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography Feneyrol, J. Giuliani, G. Ohnenstetter, D. Fallick, A. E. Martelat, J. E. Monie, Patrick Dubessy, J. Rollion-Bard, C. Le Goff, Elisabeth Malisa, E. Rakotondrazafy, A. F. M. Pardieu, V. Kahn, T. Ichangi, D. Venance, E. Voarintsoa, N. R. Ranatsenho, M. M. Simonet, C. Omito, E. Nyamai, C. Saul, M. New aspects and perspectives on tsavorite deposits |
topic_facet |
Genetic model Metasomatism Evaporites Neoproterozoic Metamorphic Mozambique Belt Tsavorite Graphitic gneiss [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography |
description |
International audience Tsavorite, the vanadian variety of green grossular, is a high value economic gemstone. It is hosted exclusively in the metasedimentary formations from the Neoproterozoic Metamorphic Mozambique Belt. The deposits are mined in Kenya, Tanzania and Madagascar and other occurrences are located in Pakistan and East Antarctica. They are located within metasomatized graphitic rocks such as graphitic gneiss and calc-silicates, intercalated with meta-evaporites. Tsavorite is found as primary deposits either in nodule (type I) or in quartz vein (type II), and in placers (type III). The primary mineralizations (types I and II) are controlled by lithostratigraphy and/or structure. For the African occurrences, the protoliths of the host-rocks were deposited at the beginning of the Neoproterozoic within a marine coastal sabkha environment, located at the margin of the Congo-Kalahari cratons in the Mozambique Ocean. During the East African-Antarctican Orogeny, the rocks underwent high amphibolite to granulite facies metamorphism and the formation of tsavorite deposits occurred between 650 and 550 Ma. The nodules of tsavorite were formed during prograde metamorphism, calcium coming from sulphates and carbonates, whereas alumina, silicates, vanadium and chromium probably came from clays and chlorite. The veins were formed during the deformation of the metasedimentary platform units which experienced shearing, leading to the formation of fault-filled veins. Metasomatism developed during retrograde metamorphism. The metasedimentary sequences are characterized by the presence of evaporitic minerals such as gypsum and anhydrite, and scapolite. Evaporites are essential as they provide calcium and permit the mobilization of all the chemical elements for tsavorite formation. The H2S-S8 metamorphic fluids characterized in primary fluid inclusions of tsavorites and the δ11B values of coeval dravite confirm the evaporitic origin of the fluids. The V2O3 and Cr2O3 contents of tsavorite range respectively from 0.05 to ... |
author2 |
Centre de Recherches Pétrographiques et Géochimiques (CRPG) Université de Lorraine (UL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Scottish Universities Environmental Research Centre (SUERC) University of Glasgow-University of Edinburgh Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement Lyon (LGL-TPE) École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL) Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Géosciences Montpellier Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS) Bureau de Recherches Géologiques et Minières (BRGM) (BRGM) University of Dar es Salaam University of Dar es Salam Faculté des Sciences Université d'Antananarivo GIA, Bangkok GIA Department of Earth and Environmental Sciences Islamabad Bahria University University of Nairobi (UoN) Akili Mineral Services Ltd Company Nairobi Akili Mineral Services Department of Mines and Geological Wundanyi Taita Taveta University (TTU) Swala Gem Traders, Arusha Swala Gem Traders |
format |
Article in Journal/Newspaper |
author |
Feneyrol, J. Giuliani, G. Ohnenstetter, D. Fallick, A. E. Martelat, J. E. Monie, Patrick Dubessy, J. Rollion-Bard, C. Le Goff, Elisabeth Malisa, E. Rakotondrazafy, A. F. M. Pardieu, V. Kahn, T. Ichangi, D. Venance, E. Voarintsoa, N. R. Ranatsenho, M. M. Simonet, C. Omito, E. Nyamai, C. Saul, M. |
author_facet |
Feneyrol, J. Giuliani, G. Ohnenstetter, D. Fallick, A. E. Martelat, J. E. Monie, Patrick Dubessy, J. Rollion-Bard, C. Le Goff, Elisabeth Malisa, E. Rakotondrazafy, A. F. M. Pardieu, V. Kahn, T. Ichangi, D. Venance, E. Voarintsoa, N. R. Ranatsenho, M. M. Simonet, C. Omito, E. Nyamai, C. Saul, M. |
author_sort |
Feneyrol, J. |
title |
New aspects and perspectives on tsavorite deposits |
title_short |
New aspects and perspectives on tsavorite deposits |
title_full |
New aspects and perspectives on tsavorite deposits |
title_fullStr |
New aspects and perspectives on tsavorite deposits |
title_full_unstemmed |
New aspects and perspectives on tsavorite deposits |
title_sort |
new aspects and perspectives on tsavorite deposits |
publisher |
HAL CCSD |
publishDate |
2013 |
url |
https://hal.archives-ouvertes.fr/hal-00853279 https://doi.org/10.1016/j.oregeorev.2013.01.016 |
geographic |
East Antarctica |
geographic_facet |
East Antarctica |
genre |
Antarc* Antarctica East Antarctica |
genre_facet |
Antarc* Antarctica East Antarctica |
op_source |
ISSN: 0169-1368 Ore Geology Reviews https://hal.archives-ouvertes.fr/hal-00853279 Ore Geology Reviews, Elsevier, 2013, 53, pp.1-25. ⟨10.1016/j.oregeorev.2013.01.016⟩ |
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info:eu-repo/semantics/altIdentifier/doi/10.1016/j.oregeorev.2013.01.016 hal-00853279 https://hal.archives-ouvertes.fr/hal-00853279 doi:10.1016/j.oregeorev.2013.01.016 |
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https://doi.org/10.1016/j.oregeorev.2013.01.016 |
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Ore Geology Reviews |
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53 |
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ftccsdartic:oai:HAL:hal-00853279v1 2023-05-15T14:05:27+02:00 New aspects and perspectives on tsavorite deposits Feneyrol, J. Giuliani, G. Ohnenstetter, D. Fallick, A. E. Martelat, J. E. Monie, Patrick Dubessy, J. Rollion-Bard, C. Le Goff, Elisabeth Malisa, E. Rakotondrazafy, A. F. M. Pardieu, V. Kahn, T. Ichangi, D. Venance, E. Voarintsoa, N. R. Ranatsenho, M. M. Simonet, C. Omito, E. Nyamai, C. Saul, M. Centre de Recherches Pétrographiques et Géochimiques (CRPG) Université de Lorraine (UL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Scottish Universities Environmental Research Centre (SUERC) University of Glasgow-University of Edinburgh Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement Lyon (LGL-TPE) École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL) Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Géosciences Montpellier Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS) Bureau de Recherches Géologiques et Minières (BRGM) (BRGM) University of Dar es Salaam University of Dar es Salam Faculté des Sciences Université d'Antananarivo GIA, Bangkok GIA Department of Earth and Environmental Sciences Islamabad Bahria University University of Nairobi (UoN) Akili Mineral Services Ltd Company Nairobi Akili Mineral Services Department of Mines and Geological Wundanyi Taita Taveta University (TTU) Swala Gem Traders, Arusha Swala Gem Traders 2013-09 https://hal.archives-ouvertes.fr/hal-00853279 https://doi.org/10.1016/j.oregeorev.2013.01.016 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.oregeorev.2013.01.016 hal-00853279 https://hal.archives-ouvertes.fr/hal-00853279 doi:10.1016/j.oregeorev.2013.01.016 ISSN: 0169-1368 Ore Geology Reviews https://hal.archives-ouvertes.fr/hal-00853279 Ore Geology Reviews, Elsevier, 2013, 53, pp.1-25. ⟨10.1016/j.oregeorev.2013.01.016⟩ Genetic model Metasomatism Evaporites Neoproterozoic Metamorphic Mozambique Belt Tsavorite Graphitic gneiss [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography info:eu-repo/semantics/article Journal articles 2013 ftccsdartic https://doi.org/10.1016/j.oregeorev.2013.01.016 2021-11-28T01:23:17Z International audience Tsavorite, the vanadian variety of green grossular, is a high value economic gemstone. It is hosted exclusively in the metasedimentary formations from the Neoproterozoic Metamorphic Mozambique Belt. The deposits are mined in Kenya, Tanzania and Madagascar and other occurrences are located in Pakistan and East Antarctica. They are located within metasomatized graphitic rocks such as graphitic gneiss and calc-silicates, intercalated with meta-evaporites. Tsavorite is found as primary deposits either in nodule (type I) or in quartz vein (type II), and in placers (type III). The primary mineralizations (types I and II) are controlled by lithostratigraphy and/or structure. For the African occurrences, the protoliths of the host-rocks were deposited at the beginning of the Neoproterozoic within a marine coastal sabkha environment, located at the margin of the Congo-Kalahari cratons in the Mozambique Ocean. During the East African-Antarctican Orogeny, the rocks underwent high amphibolite to granulite facies metamorphism and the formation of tsavorite deposits occurred between 650 and 550 Ma. The nodules of tsavorite were formed during prograde metamorphism, calcium coming from sulphates and carbonates, whereas alumina, silicates, vanadium and chromium probably came from clays and chlorite. The veins were formed during the deformation of the metasedimentary platform units which experienced shearing, leading to the formation of fault-filled veins. Metasomatism developed during retrograde metamorphism. The metasedimentary sequences are characterized by the presence of evaporitic minerals such as gypsum and anhydrite, and scapolite. Evaporites are essential as they provide calcium and permit the mobilization of all the chemical elements for tsavorite formation. The H2S-S8 metamorphic fluids characterized in primary fluid inclusions of tsavorites and the δ11B values of coeval dravite confirm the evaporitic origin of the fluids. The V2O3 and Cr2O3 contents of tsavorite range respectively from 0.05 to ... Article in Journal/Newspaper Antarc* Antarctica East Antarctica Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) East Antarctica Ore Geology Reviews 53 1 25 |