Costin, D.

Damian, F.

Damian, Gh.

English

Damian F.

Damian Gh.

Costin D.

University of Szeged

Acta Miner alogica-Petrographica, Szeged, XLi, Supplementum, 2000 BISMUTH SULPHOSALTS IN THE NEOGENE HYDROTHERMAL VEIN ORES FROM THE BAIA MARE ORE DISTRICT DAMIAN, F., DAMIAN, Gh. (North University of Baia Mare, Department of Geology, Baia Mare, Romania) & COSTIN, D. (Babe§-Bolyai University, Department of Mineralogy-Petrometallogeny, Cluj-Napoca, Romania) E-mail: damgeo@univer.ubm.ro Bismuth minerals are mainly represented by Bi-Cu-Pb phases. Bi-Pb with Ag and Bi-Ag have been identified only in two vein ore deposits, i.e. at Nistru and Baiut, in the western and eastern part of the area, respectively. The presence of bismuth sulphosalts in several occurrences of the Baia Mare area has recently been documented by COOK & DAMIAN (1997) and DAMIAN (1999). The Bi sulphosalts from Nistru and Baiut are present within the cupriferous sequences with gold and silver content which are connected with the Pannonian calc-alkaline igneous rocks of subvolcanic character (porphyry quartz-monzodiorites, porphyry microdiorites). The Bi sulphosalts from Nistru and some of the Bi minerals from Baiut represent the first chemically documented occurrences. In both occurrences the Bi sulphosalts are mainly represented by the members of the lillianite homologous series. The compositional homogenity is emphasized by microprobe analyses yielding the general formula Pb1.47_K97Ago.39-o.66Fe0.03-o.19Cu0.07-0.032Bi2.40-2.53Seo.02S5.48-5.79), as well as by a small deviation from the theoretical line N = 4 of the members of the lillianite-gustavite series. Some mineral phases reminiscent of vikingite (N = 5.08) and heyrovskite are present mainly at Baiut. The Bi minerals of the lillianite-gustavite series occur as inclusions in chalcopyrite or quartz and contain minute gold grains. In the Nistru ores the Cu-Pb-Bi sulphosalts are represented by compositions varying from pekoite (Cuo.55-o.7oFe0.06-0.33Pbo.2o-o.9o Bi714_74gSe0.03-0.35Sii.5o-i2.26) to krupkaite (Cui.88-2.17Fe0.o8-o.27Pb1.85-1.97Bi5.78-6.o4S11.98-12.19X with subordinate participation of gladite (Cui 3oFeo.i3Pbi.2iBi666Sn 58). They are subordinately associated with matildite (Ago.87-o.94Cuo.os Bio.94-1S1.s7)- Cosalite has been identified in a few cases as a result of Bi enrichment and Pb depletion (Pbi.53-1.57 Ag0.013-o.014Fe0.07-o.1Cu0.26-o.33Bi1.85-1.93S4.58-4.76)-References COOK, N.J. & DAMIAN, Gh. (1997). Romanian Journal of Mineralogy. Abstracts Volume, 78(1): 15-16. DAMIAN, F. (1999). Romanian Journal of Mineralogy. Abstracts Volume, 79(1): 27. 27 

Bismuth sulphosalts in the neogene hydrothermal vein ores from the Baia Mare ore district

http://acta.bibl.u-szeged.hu/24923/1/mineralogica_041_suppl_027.pdf

Bismuth sulphosalts in the neogene hydrothermal vein ores from the Baia Mare ore district

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