Petrogenesis of Archean PGM-bearing chromitites and associated ultramafic-mafic-anorthositic rocks from the Guelb el Azib layered complex (West African craton, Mauritania)
peer reviewed The Archean Guelb el Azib layered complex (GAC) in the West African craton of Mauritania is composed of an association of serpentinites, chromitites, amphibolites and anorthosites with few fine-grained amphibolite dykes. The complex forms tectonic slices in 2.9-3.5. Ga TTG gneiss terra...
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ftorbi:oai:orbi.ulg.ac.be:2268/173793 2024-04-21T08:04:00+00:00 Petrogenesis of Archean PGM-bearing chromitites and associated ultramafic-mafic-anorthositic rocks from the Guelb el Azib layered complex (West African craton, Mauritania) Berger, J. Diot, H. Lo, K. Ohnenstetter, D. Féménias, O. Pivin, M. Demaiffe, D. Bernard, A. Charlier, Bernard 2013 https://orbi.uliege.be/handle/2268/173793 https://orbi.uliege.be/bitstream/2268/173793/1/Berger%20et%20al%202013.pdf https://doi.org/10.1016/j.precamres.2012.10.005 en eng Elsevier urn:issn:0301-9268 https://orbi.uliege.be/handle/2268/173793 info:hdl:2268/173793 https://orbi.uliege.be/bitstream/2268/173793/1/Berger%20et%20al%202013.pdf doi:10.1016/j.precamres.2012.10.005 scopus-id:2-s2.0-84875085438 open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess Precambrian Research, 224, 612-628 (2013) Anorthosite Archean tholeiite Granulites Layered complex Mafic-ultramafic rocks Archean Mauritania West African Craton Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique journal article http://purl.org/coar/resource_type/c_6501 info:eu-repo/semantics/article peer reviewed 2013 ftorbi https://doi.org/10.1016/j.precamres.2012.10.005 2024-03-27T14:56:39Z peer reviewed The Archean Guelb el Azib layered complex (GAC) in the West African craton of Mauritania is composed of an association of serpentinites, chromitites, amphibolites and anorthosites with few fine-grained amphibolite dykes. The complex forms tectonic slices in 2.9-3.5. Ga TTG gneiss terrains in close association with supracrustal rocks (BIFs, impure marbles, amphibolites). It was affected by a main granulite-facies grade metamorphism (up to 900. °C at 5-6. kbar) with subsequent retrogression in amphibolite and greenschist facies conditions. The preserved igneous macrostructures, the mineral compositions and the nature of relic magmatic assemblages have been used to constrain the composition of the parental melts and the conditions of crystallization. According to petrological observations and to comparison with experimental data, the formation of the complex can be explained by fractionation of a slightly hydrous high-alumina basaltic melt at low pressure. The early fractionation of olivine and the absence of massive clinopyroxene fractionation before plagioclase saturation led to crystallization of highly calcic plagioclase with Fe-, Al-rich but Cr-poor chromite from a hydrous tholeiitic parental magma, similar to worldwide Archean tholeiites. The complex shares many similarities with Archean anorthosite layered complexes, possibly formed in a supra-subduction zone environment according to results obtained on similar 2.9-3.0. Ga complexes from Greenland and India (namely Fiskenaesset and Sittampundi). Three phases of PGE mineralization affected the GAC chromitites: (i) igneous crystallization of laurite; (ii) formation of late magmatic IPGE sulpho-arsenides (irarsite-hollingworthite) and (iii) hydrothermal Pt-Pd mineralization represented by sperrylite and rustenburgite. © 2012 Elsevier B.V. Article in Journal/Newspaper Greenland University of Liège: ORBi (Open Repository and Bibliography) Precambrian Research 224 612 628 |
institution |
Open Polar |
collection |
University of Liège: ORBi (Open Repository and Bibliography) |
op_collection_id |
ftorbi |
language |
English |
topic |
Anorthosite Archean tholeiite Granulites Layered complex Mafic-ultramafic rocks Archean Mauritania West African Craton Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
spellingShingle |
Anorthosite Archean tholeiite Granulites Layered complex Mafic-ultramafic rocks Archean Mauritania West African Craton Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique Berger, J. Diot, H. Lo, K. Ohnenstetter, D. Féménias, O. Pivin, M. Demaiffe, D. Bernard, A. Charlier, Bernard Petrogenesis of Archean PGM-bearing chromitites and associated ultramafic-mafic-anorthositic rocks from the Guelb el Azib layered complex (West African craton, Mauritania) |
topic_facet |
Anorthosite Archean tholeiite Granulites Layered complex Mafic-ultramafic rocks Archean Mauritania West African Craton Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
description |
peer reviewed The Archean Guelb el Azib layered complex (GAC) in the West African craton of Mauritania is composed of an association of serpentinites, chromitites, amphibolites and anorthosites with few fine-grained amphibolite dykes. The complex forms tectonic slices in 2.9-3.5. Ga TTG gneiss terrains in close association with supracrustal rocks (BIFs, impure marbles, amphibolites). It was affected by a main granulite-facies grade metamorphism (up to 900. °C at 5-6. kbar) with subsequent retrogression in amphibolite and greenschist facies conditions. The preserved igneous macrostructures, the mineral compositions and the nature of relic magmatic assemblages have been used to constrain the composition of the parental melts and the conditions of crystallization. According to petrological observations and to comparison with experimental data, the formation of the complex can be explained by fractionation of a slightly hydrous high-alumina basaltic melt at low pressure. The early fractionation of olivine and the absence of massive clinopyroxene fractionation before plagioclase saturation led to crystallization of highly calcic plagioclase with Fe-, Al-rich but Cr-poor chromite from a hydrous tholeiitic parental magma, similar to worldwide Archean tholeiites. The complex shares many similarities with Archean anorthosite layered complexes, possibly formed in a supra-subduction zone environment according to results obtained on similar 2.9-3.0. Ga complexes from Greenland and India (namely Fiskenaesset and Sittampundi). Three phases of PGE mineralization affected the GAC chromitites: (i) igneous crystallization of laurite; (ii) formation of late magmatic IPGE sulpho-arsenides (irarsite-hollingworthite) and (iii) hydrothermal Pt-Pd mineralization represented by sperrylite and rustenburgite. © 2012 Elsevier B.V. |
format |
Article in Journal/Newspaper |
author |
Berger, J. Diot, H. Lo, K. Ohnenstetter, D. Féménias, O. Pivin, M. Demaiffe, D. Bernard, A. Charlier, Bernard |
author_facet |
Berger, J. Diot, H. Lo, K. Ohnenstetter, D. Féménias, O. Pivin, M. Demaiffe, D. Bernard, A. Charlier, Bernard |
author_sort |
Berger, J. |
title |
Petrogenesis of Archean PGM-bearing chromitites and associated ultramafic-mafic-anorthositic rocks from the Guelb el Azib layered complex (West African craton, Mauritania) |
title_short |
Petrogenesis of Archean PGM-bearing chromitites and associated ultramafic-mafic-anorthositic rocks from the Guelb el Azib layered complex (West African craton, Mauritania) |
title_full |
Petrogenesis of Archean PGM-bearing chromitites and associated ultramafic-mafic-anorthositic rocks from the Guelb el Azib layered complex (West African craton, Mauritania) |
title_fullStr |
Petrogenesis of Archean PGM-bearing chromitites and associated ultramafic-mafic-anorthositic rocks from the Guelb el Azib layered complex (West African craton, Mauritania) |
title_full_unstemmed |
Petrogenesis of Archean PGM-bearing chromitites and associated ultramafic-mafic-anorthositic rocks from the Guelb el Azib layered complex (West African craton, Mauritania) |
title_sort |
petrogenesis of archean pgm-bearing chromitites and associated ultramafic-mafic-anorthositic rocks from the guelb el azib layered complex (west african craton, mauritania) |
publisher |
Elsevier |
publishDate |
2013 |
url |
https://orbi.uliege.be/handle/2268/173793 https://orbi.uliege.be/bitstream/2268/173793/1/Berger%20et%20al%202013.pdf https://doi.org/10.1016/j.precamres.2012.10.005 |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
Precambrian Research, 224, 612-628 (2013) |
op_relation |
urn:issn:0301-9268 https://orbi.uliege.be/handle/2268/173793 info:hdl:2268/173793 https://orbi.uliege.be/bitstream/2268/173793/1/Berger%20et%20al%202013.pdf doi:10.1016/j.precamres.2012.10.005 scopus-id:2-s2.0-84875085438 |
op_rights |
open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.precamres.2012.10.005 |
container_title |
Precambrian Research |
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224 |
container_start_page |
612 |
op_container_end_page |
628 |
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1796943644797698048 |