||The relevance of the work is to determine the mineral forms of gold and silver in the vein bodies of the Shakhtamny ore district, where the largest Shakhtaminskaya gold placer has been known since the 19th century. The purpose of the work is to determine the contents of gold and silver and study their mineral forms. The object of study is sulfide-quartz-dolomite vein formations, and the subject is mineral associations containing gold and silver. The methodology includes the use of optical and electron microscopy.
For the first time using the complex of modern methods, the mineral composition of the manifestations of gold and silver was studied within the Shakhtaminskoye ore district. A relatively high silver content of fragments of fine-grained carbonate-quartz veins containing chalcopyrite, sphalerite, pyrite, galena, sulfosalts of tetrahedritical composition, as well as native silver and gold was established. A feature of tetrahedrite is the enrichment of zinc (6.52…7.73 %) and the relatively low content of arsenic in it. The ratio of antimony and arsenic is in the range of 2.64…13.33.
The calculation of the formula coefficients showed a sulfur deficiency, replaced by an excess of As. A typical tetrahedrite formula indicates the distribution of copper in three positions, where in two of them it is replaced by Zn, Fe and Ag: (Cu6[(Cu3.78,Ag0.22)4(Cu0.03,Fe0.2,Zn1.67)1,9](Sb3.59,As0.5)4.09(S12.96,As0.04)13.0.
The sharp predominance of Sb over As is a feature of faded ores of quartz-molybdenite deposits. This is due to the limited development of arsenic mineralization in deposits of the molybdenum-quartz mineral type of the molybdenum-porphyry formation. For the first time for the Shakhtaminskoye ore field, silver enrichment of tetrahedrite (1.08…1.72 %) was revealed. In this regard, it is recommended to study the silver content of technosoils of the old tailing dump, since only molybdenite was extracted from the ores of the Shakhtaminskоyе molybdenum deposit. Native silver and gold were discovered for the first time. Moreover, silver contains up to 44.45 % Au, and gold 17.41 % Ag. These features of native gold and silver indicate that the studied fragments of the quartz-carbonate vein belong to the deposit of a shallow gold-silver formation
||1. Baleyskoye rudnoye pole (Baley ore field) / ed. N. P. Laverov. Moscow: TSNIGRI, 1984. 272 p.
2. Bybin F. F. Entsyclopedia of Zabaikaliya (Encyclopedia of Transbaikalia) / ch. ed. R. F. Geniatulin. Novosibirsk: Science, 2003, vol. 4, pp. 369.
3. Yeremin O. V., Yurgenson G. A., Epova Ye. S. Geosfernye issledovaniya (Geosphere studies), 2018, no. 3, pp. 43–50.
4. Yershov V. V. Entsiklopediya Zabaykaliya (Encyclopedia of Transbaikalia) / ch. ed. R. F. Geniatulin. Novosibirsk: Science, 2006, vol. 4, pp. 369.
5. Mozgova N. N. Nestehiometriya i gomologicheskiye ryady sulfosoley (Non-stoichiometry and homologous series of sulfosalts). Moscow: Science, 1985. 264 p.
6. Petrovskaya S. G. Geologiya i geofizika (Geology and geophysics), 1973, no. 9, pp. 77–84.
7. Pokalov V. T. Rudnomagmaticheskiye sistemy gidrotermalnyh mestorozhdeniy (Ore-magmatic systems of hydrothermal deposits). Moscow: Nedra, 1992. 288 p.
8. Prokofiyev V. Yu., Kiseleva G. D., Dolomanova-Topol A. A., Kryazhev S. G., Zorina L. D., Krasnov A. N., Borisovskiy S. Ye., Trubkin N. V., Magazina L. V. Geologiya rudnyh mestorozhdeniy (Geology of ore deposits), 2017, vol. 59, no. 6, pp. 542–575.
9. Sidorenko V. V. Geologiya i petrologiya Shahtaminskogo intruzivnogo kompleksa (Geology and petrology of the Shakhtaminsky intrusive complex). Moscow; Leningrad: USSR Academy of Sciences, 1961. 102 p.
10. Sotnikov V. I., Berzina A. P., Gimon V. O. Mectorozhdeniya Zabaykaliya (Deposits of Transbaikalia) / ed. N. P. Laverov. Moscow: Geoinformmark, 1995, vol. 1, is. 1, pp. 187–192.
11. Yurgenson G. A., Filenko R. A. Geosfernye issledovaniya (Geosphere studies), 2018, no. 4, pp. 21–31.
12. Back M. E. Fleischer’s glossary of minerаl species 2014 (Fleischer’s glossary of minerаl species 2014). Tucson: The Minerelogical Record Inc., 2014. 420 p.
13. Kudrjashova V. I. Proceedings of the Russian Mineralogical Society (Proceedings of the Russian Mineralogical Society), 1995, no. 6, pp. 108–120.
14. Majzlan J., Kiefer S., Hermann J., Stevko M., Sejkora M., Chovan M., Lanczos T., Lazarov M., Langenhorst F., Radkova A., Jamieson H., Milovsky R. Chemical Geology (Chemical Geology), 2018, vol. 488, pp. 1–20.
15. Shimizu M., Kato A., Matsubara S., Criddle A. J., Stanley С. J. Mining Magazine (Mining Magazine), 1993, vol. 57, no. 4, pp. 643.