Thériault Robert D., Barnes Sarah-Jane et Severson Mark J.. (2000). Origin of Cu-Ni-PGE Sulfide mineralization in the Partridge River Intrusion, Duluth Complex, Minnesota. Economic Geology and the Bulletin of the Society of Economic Geologists, 95, (5), p. 929-943.
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URL officielle: http://geoscienceworld.org/georef/2001-003063
Résumé
Four sub-economic Cu-Ni-PGE deposits occur near the base of the Partridge River mafic layered intrusion along the NE margin of the Duluth complex; the host troctolitic rocks are in contact with sulphide-bearing metasedimentary rocks of the Virginia formation. Three main types of sulphide mineralization are recognized: 1) PGE-poor disseminated sulphides, 2) PGE-rich disseminated sulphides and 3) semi-massive to massive sulphides. The PGE-poor disseminated sulphides occur in the lower 250 m of the intrusion; their mineralogy and geochemistry suggest that the magma had undergone substantial contamination. The PGE-rich disseminated sulphides occur directly beneath ultramafic layers and show few signs of contamination; they appear to have formed at high ratios of silicate magma to sulphide melt. The semi-massive and massive sulphides occur mainly as veins and lenses along the basal contact and within the country rocks; they are zoned with pyrrhotite-rich (Fe-rich) and chalcopyrite-cubanite-rich (Cu-rich) portions. It is concluded that three different processes operated in sequence from magma emplacement to complete crystallization of the sulphides: 1) country-rock assimilation, 2) interaction between sulphide melt and silicate magma and 3) fractional crystallization of the sulphide melt.
Type de document: | Article publié dans une revue avec comité d'évaluation |
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ISSN: | 0361-0128 |
Volume: | 95 |
Numéro: | 5 |
Pages: | p. 929-943 |
Version évaluée par les pairs: | Oui |
Date: | 2000 |
Sujets: | Sciences naturelles et génie > Sciences naturelles > Sciences de la terre (géologie, géographie) |
Département, module, service et unité de recherche: | Départements et modules > Département des sciences appliquées > Unité d'enseignement en sciences de la Terre |
Mots-clés: | assimilation, chemical composition, copper ores, country rocks, Duluth Complex, emplacement, inclusions, intrusions, magma contamination, massive deposits, massive sulfide deposits, metal ores, mineral composition, mineral deposits, genesis, mineralization, Minnesota, nickel ores, Paleoproterozoic, Partridge River Intrusion, platinum ores, Precambrian, Proterozoic, Saint Louis County Minnesota, structural controls, sulfides, United States, upper recambrian, Virginia Formation, xenoliths |
Déposé le: | 14 juin 2016 13:16 |
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Dernière modification: | 09 déc. 2016 14:56 |
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