Formation Features of Pyrite and Arsenopyrite Metacrystals of the Bobrykove Gold Deposit (Donbas)

UDC 549.324 : 552.5 (477.6)

O.V. Tsilmak, L.Z. Skakun

Ivan Franko National University of Lviv

Hrushevsky Str., 4, Lviv, Ukraine, 79005


Formation Features of Pyrite and Arsenopyrite Metacrystals of the Bobrykove Gold Deposit (Donbas)

Language: Ukrainian

Mineralogical journal 2015, 37 (3): 28-36

Abstract: The paper presents the results of internal structure of pyrite and arsenopyrite metacrystals and determination of the degree of epigenetic changes of host rocks of the Bobrykove gold deposit. The Bobrykove gold deposit is located in the Donbas region of eastern Ukraine within the Nagolny Ridge structure. The Bobrykove deposit is located within the southern part of the Main anticline of Donbas 11 km long and 2.5 km wide. The deposit is confined to the crossing of the deep fault zones. Mineralization is controlled by NW-NNW trending anticline hinge, and occurs as concordant and discordant quartzcarbonate tension veins and stockworks. The degree of epigenetic changes of host rocks is designed by illite crystallinity. To detect the internal texture of metacrystals in the process of structural etching the following reagents are used: for arsenopyrite — K2MnO4 : H2SO4 = 1 : 1, for pyrite — HNO3 + CaF2. The areas of pyrite blocks and quartz grains from metacrystals and wall rocks, respectively, were statistically compared. Based on the complex techniques the authors have made key conclusions: 1. Host rocks of the Bobrykove gold deposit on the metamorphic stage under the influence of a deep magma source have undergone recrystallization and metamorphism, which extent has reached the greenschist facies. 2. Metacrystals of pyrite and arsenopyrite were formed before recrystallization and metamorphization of rock matrix by replacing the minerals composing the rock on the stage of anchimetamorphism (prehnite-pumpellyite facies).

Keywords: Bobrykove gold deposit, host rock, anchizone, epizone, illite crystallinity, metacrystal, internal structure.


1. Bushmakin, A.F. (1985), in Grigoryev, D.P. (ed.), Prob lems of Mineral Ontogeny, Nauka, Leningrad, pp. 73-82.
2. Glikin, A.E. (2004), Polymineral-Metasomatic Crystallo genesis, Neva, St. Petersburg, 300 p.
3. Gordienko, V.V. (1999), Density Models of the Tectonosphere of the Territory of Ukraine, Intellect, Kiev, 100 p.
4. Grigoryev, D.P. and Zhabin, A.G. (1975), Ontogeny of Minerals. Individuals, Nauka, Moscow, 340 p.
5. Kuznetsov, Yu.A., Kvasnytsya, V.N. and Ponomarenk o, A.P. (1981), Mineralogical evaluation criteria of ore, Nauka, Leningrad, pp. 181-186.
6. Kurylo, M.V. and Burmistrova, V.V. (1981), Proc. of the URSR Acad. of Sci., Ser. B, Kyiv, Ukraine, No 12, pp. 20-25.
7. Kurylo, M., Dyschuk, Yu., Cherniyenko, I. and Ba lan, E. (2009), Ukrainian Geologist, No 1-2, pp. 105-114.
8. Lazarenko, E.K., Panov, B.S. and Pavlyshyn, V.I. (1975), The mineralogy of the Donetsk Basin, Pt. 2, Naukova dumka, Kiev, 502 p.
9. Shumlyansky, V.O., Derevska, K.I., Dudar, T.V., Ivant yshyna, O.M., Subbotin A.H., Bezugla, M.V. and Aleks androv, O.L. (2003), Lithogenesis and Hypogenic Ore Formation in Sedimentary Strata of the Ukraine, Znannia Ukrainy, Kyiv, 272 p.
10. Shumlyansky, V.A., Demikhov, Yu.N., Derevskaya, E.I., Dudar, T.V., Zelenskiy, S.A., Zinchuk, I.N., Ivantys hyn a, O.M., Kurylo, M.V. and Syngaevsky, V.D. (1994), Geol. Journ., Kyiv, Ukraine, No 3, pp. 95-106.
11. Frey, M. and Robinson, D. (eds) (1999), Low-Grade Metamorphism, Blackwell Publ. Ltd., Oxford, UK, 328 p.
12. Passchier, C.W. and Trouw, R.A.J. (2005), Microtectonics, 2nd ed., Springer-Verlag, Berlin Heidelberg, Germany, 353 p.
13. Tischendorf, G., Rieder, M., Förster, H.-J., Gottes mann, B. and Guidotti, Ch.V. (2004), Miner. Mag., Vol. 68 No 4, pp. 649-667.
14. Verdel, C., Niemi, N. and van der Pluijm, B.A. (2011), J. Geol., Vol. 119 No 4, pp. 419-437.