Geologia Croatica (Oct 2011)
Cobalt, nickel, wolfram, cadmium, selenium, silver and gold-bearing mercurian tetrahedrite from the Saski Rad barite-siderite deposit in the Mid-Bosnian Schist Mts.
Abstract
In the Saski Rad barite-siderite ore deposit, Hg-tetrahedrite is the main ore mineral, pyrite and some others are only accessories. Two tetrahedrite samples (fresh and weathered) have been analysed in detail: major and minor components, constituent trace elements, REE, and δ34SCDT values. The following microconstituents have been detected: Ni 71 ppm (in fresh sample) and 70 ppm (in weathered sample); Co 113 and 90 ppm; Cd 27 and 20 ppm; W 20 and 5 ppm, Bi 2500 and 1613 ppm; Se >100 and 72 ppm and Au 11 and 9 ppm. These values have been compared with the only currently available analysis of Hg-tetrahedrite from the Duboki Vagan near Kreševo in the Mid-Bosnian Schist Mts. (MBSM) carried out by JURKOVIĆ et al. (2010): Ni 266.2 ppm; Co 63.5 ppm, Cd 319.6 ppm; Bi 1466.0 ppm; Au 38.96 ppm which also agrees with our analysis of Hg-tetrahedrite from the Brixlegg barite deposit in Tyrol, Austria: Co 234.4 ppm; Cd 160.5 ppm; W 6.7 ppm; Sn 1.0 ppm; Bi 909.1 ppm; Se > 100 ppm and Au 2.3 ppm. The δ34SCDT isotope values of six tetrahedrites from the Saski Rad are on average –10.11‰, those of three tetrahedrites from the Duboki Vagan –10,05‰ and of the tetrahedrite from the Brixlegg deposit –1.60‰. The ΣREE content is lower in two analysed tetrahedrites from the Saski Rad deposit (10 ppm) compared to the tetrahedrite from Duboki Vagan (15 ppm) and the tetrahedrite from Brixlegg (17.4 ppm). The analysed barite sample from the Saski Rad deposit does not contain microconstituents typical of Hg-tetrahedrite. The distribution and genetic signifi cance of some trace elements, tetrahedrite microconstituents, REE and siderite isomorphic components in the seven most important genetic and paragenetic types of ore deposits in the MBSM and South-Eastern Bosnia have been commented upon.
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