gîte volcanogène de sulfures massifs
- Domaine
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- géologie
Note :
[...] les filon-couche [sic] sub-volcaniques de pair avec les centres éruptifs felsiques ont joué un rôle important dans la production des dépôts volcanogènes de sulfures massifs dans la Formation de Waconichi [...].
Termes :
Terme associé :
- amas sulfuré volcano-sédimentaire n. m. France
Traductions
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anglais
Auteur : Université Laval,Définition
Stratabound, lenticular body of massive pyritic mineralization containing variable amounts of chalcopyrite, sphalerite, and galena in layered volcanic rocks generally formed subaqueously by volcanic-fumarolic activity.
Notes :
Hutchinson [...] has grouped the massive sulfide deposits according to their predominant ore metal content, taking into account their tectonic habitat. There are two broad groups based on bulk composition of the volcanic assemblage: those in predominantly basaltic or oceanic assemblages [Cyprus-type, also called cupreous pyrite deposits] and those in more felsic basalt-andesite-rhyolite assemblages. Copper is the chief ore element in the first group, and zinc and lead, with copper, characterize the second. Deposits of both groups, of course, contain excess purite.
Base metal massive sulfide deposits within felsic volcanic piles are typically zoned from a copper-rich base to a zinc ≷ lead-rich top. The origin of the compositional zoning, whereby zinc and lead are most abundant toward the hanging-wall side of the massive ore with copper increasing toward the footwall and passing into Cu-rich stringer ore, has not been adequately explained.
The massive ore is strata-bound and may be stratiform, it may comprise up to 100 percent of the total sulfide present. Many massive sulfide ore lenses have a substantial component of discordant vein-type sulfide mineralization, the stringer ore, mainly in the footwall strata. The stringer ore is also referred as "disseminated" or "vein" ore.Termes :
- volcanogenic massive sulfide deposit
- volcanogene massive sulfide deposit
Termes associés :
- volcanic-associated massive sulfide deposit
- volcanic massive sulphide deposit
- base-metal-rich volcanogenic massive sulphide deposit
- volcanogenic massive sulfide ore
- volcanogene massive sulphide ore
- exhalative massive sulfide ore
- synvolcanic massive sulphide ore