T 44 The Aktepe silver-arsenide deposits, Uzbekistan [Text] / V. A. Kovalenker, V. L. Rusinov, A. E. Kabo, J. L. Jambor // Exploration & Mining Geology. - 1995. - Vol. 4, № 2. - P111-119 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ARSENIDE -- GABBRO -- ORE DEPOSITION -- ORE MINERALOGY -- SILVER Аннотация: Ores rich in native silver at the Aktepe orefield near Tashkent, Uzbekistan, are similar to the arsenide-silver ores of the Cobalt-Gowganda region, Canada. The Aktepe ores occur as shoots and lenses in narrow fissures within a middle Paleozoic gabbro massif which is surrounded by Upper Paleozoic felsic volcanics and syenite intrusions. Widespread deuteric propylitization of the massif preceded ore deposition. The ore consists mainly of native silver, which is accompanied by native arsenic and bismuth, allargentum, dyscrasite, acanthite, numerous sulfides and sulfosalts, and by a Ni-Co-Fe arsenide and sulfarsenide assemblage similar to that of Cobalt-Gowganda. The Aktepe gangue minerals are mainly calcite, ferroan dolomite, and chlorite, and the veins are bordered by a wallrock-alteration assemblage of sericite-quartz-carbonate-pyrite. A difference from Cobalt-Gowganda is that the Aktepe carbonates are iron-rich, a feature which is attributed to a genetic relationship with the iron-rich host gabbros. -Authors???? |