Mineralogical expression of silver in copper sulfides of Tagmout deposit (Eastern Anti-Atlas, Morocco)

Autor: Aissa Mohamed, Moussaid Azizi, Abaouz Ali, Mezougane Hafid, El Basbas Abdelaziz, El Azmi Mohamed, Souiri Muhammad, Kharis Abdel-ali
Rok vydání: 2019
Předmět:
Zdroj: Arabian Journal of Geosciences. 12
ISSN: 1866-7538
1866-7511
Popis: Tagmout deposit, located in the Saghro inlier, about 80 km from the town of Ouarzazate, contains Cu-Ag copper mineralizations. These mineralizations are embedded in various intrusive magmatic rocks ranging from gabbro to granite and controlled by microgranite dykes. The copper mineralizations are mainly represented by sulfides (chalcopyrite, bornite, and chalcocite), secondarily by late carbonates (malachite and azurite). Silver is expressed either as a minor constituent of copper sulfides or as a late copper-silver sulfide stromeyerite CuAgS. The petrological and mineralogical studies coupled with chemical examination with SEM and electron microprobe of copper sulfides revealed significant contents of Ag (up to 3% by weight in chalcocite) and other trace elements Sb, Zn, As, and especially Cd (~ 600 ppm) and Pb (~ 1.25 wt%). The Tagmout mineralization was set up in two stages: the first with Cu, Pb, and Zn (bornite, chalcopyrite, galena, and sphalerite) and the second with Ag (stromeyerite and Ag-bearing copper sulfides). Ag is incorporated into Cu sulfides by substitutions: (i) Cu by Ag in chalcopyrite and bornite, and Cu by (Ag + Pb) in chalcocite. These substitutions are buttressed by the good negative correlation between these elements, established from the chemical analyses of chalcopyrite, bornite, and chalcocite ; (ii) the presence of significant levels of Pb, and the total absence of Cd in the chemical composition of chalcocite which is almost free of Fe.
Databáze: OpenAIRE
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