Pyrite from Zones of Mz-Kz Reactivation of Large Faults on the Eastern Slope of the Ural Mountains, Russia

Authors: O. B. Azovskova, А. А. Malyugin, А. А. Nekrasova, M. Yu. Yanchenko

Abstract:

Pyritisation halos are identified in weathering crusts and unconsolidated formations at five locations within large fault structure of the Urals’ eastern slope. Electron microscopy reveals the presence of inclusions and growths on pyrite faces – normally on cubic pyrite with striations, or combinations of cubes and other forms. Following neogenesis types are established: native elements and intermetallic compounds (including gold and silver), halogenides, sulphides, sulfosalts, tellurides, sulphotellurides, selenides, tungstates, sulphates, phosphates, carbon-based substances. Direct relationship is noted between amount and diversity of such mineral phases, and proximity to and scale of ore-grade mineralization. Gold and silver, both in native form and within tellurides, presence of lead (galena, native lead), native tungsten, and, possibly, molybdenite and sulfosalts can indicate gold-bearing formations. First find of native tungsten in the Urals is for the first time – in crystallised and druse-like form. Link is suggested between unusual mineralization and “reducing” hydrothermal fluids from deep-seated faults at later stages of Urals’ reactivation. 

Keywords: Gold in weathering crust, low temperature metasomatism, pyrite, native tungsten, Urals.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1086921

References:

[1] V. N. Sazonov, V. N. Ogorodnikov, V. A. Koroteyev, Yu. A. Polenov, Urals Gold Deposits. Yekaterinburg: UGGGA, 2001.
[2] O. B. Azovskova, K. A. Zubarev, J. L. Ronkin, A. A. Nekrasova, L. O. Magazina, “First data on pyrite geochemistry in zones of Meso- Cenozoic reactivation in the Middle Urals, connection with endogenous gold mineralisation”, in. Proc. Internat. Conf. Problems of geology of Ore Deposits, Mineralogy, Petrology, and Geochemistry, Moscow, 2008. pp. 113-117.
[3] O. B. Azovskova, A. P. Mikhailov, A. A. Nekrasova, A. I. Zubkov, “Development of placer gold ore systems in long-lived deep-seated fault zones (example of Serovsko-Maukski Fault, Middle Urals)”in Proc. II Intern. Mining and Geol. Forum Gold of North Pacific Margin, Magadan, 2011. pp. 50-52 (Eng.).
[4] O. B. Azovskova, Y. V. Schegolkov, S. P. Glavatskih, A. A. Nekrasova, “Pyrite from haloes of reactivation of large fault structures: certain typomorphic features and association with carbon metasomatism”. // Proc. Intern. Seminar Crystalline and Solid Non-crystalline State of Mineral Substance, Syktyvkar, 2012. pp. 105-108.
[5] A. P. Sigov, Metallogeny of Mesozoic and Ceinozoic&&& in the Urals. Moscow: Nedra, 1969.
[6] O. B. Azovskova, А. А. Nekrasova, Yu. V. Schegolkov, “Description of “young” pyrite mineralisation of Serovsko-Maukski Fault zone (Aivinsko-Yemekhski block)”. Bulletin of the Urals Branch of RMS) No. 8, Yekaterinburg. 2011. pp. 5-12.
[7] B. S. Andreyev, Pyrite in gold Ore Deposits. Moscow: Nauka, 1992.
[8] G. A. Yurgenson, Typomorphism and Ore Formations. Novosibirsk: Nauka, 2003.
[9] O. N. Gryaznov, A. G. Barannikov, K. P. Savelieva, Unconventional types of gold-argillisite mineralization in Mesozoic structures of the Urals. // Izvestiya UGGU, Iss. 22, pp. 41-53, 2007.
[10] A. I. Grabezhev, V. I. Sotnikov, A. A. Borovikov, O. B. Azovskova “Genetic Typification of Gumeshki Copper-Skarn Deposit (Middle Urals). // Reports of the Academy of Sciences, Vol. 380, No. 2, pp. 242- 245, 2001.
[11] S. F. Glavatskikh, N. V. Trubkin, “First Finds of native Tungsten and Silver in exhalation Products of the Great Tolbachik Fissure Eruption, Kamchatka. Reports of the Academy of Sciences, vol. 373-А, no. 6. pp. 1282-1285, 2000.
[12] A.E. Lukin, “On native tungsten in rocks of petroliferous complexes”, Reports of the National Academy of Sciences of Ukraine, 2009, No. 2, pp. 121-130.
[13] “Organoelemental Chemistry Methods. Copper, Scandium, Titanium, Vanadium, Chromium, manganese Subgroups”, book 2, A. N. Nesmeyanova and K. A. Konenkova, Ed., Moscow: 1974.
[14] C. B. Pamplin, T. W. Hayton, P. Legzdins, “Tungsten: Organometallic Chemistry”, Published Online: 15 DEC 2011 DOI: 10.1002/9781119951438.eibc0233. Published in Encyclopedia of inorganic and bioinorganic chemistry.
[15] V. E. Ivanov, E. P. Nechiporenko, V. M. Krivoruchko, V. V. Sagalovich, Crystallisation of High-Melting-Point Metals from Gas Phase, Moscow: Atomizdat, 1974.
[16] V. L. Tauson, D. N. Babkin, T. M. Pastushkova et al., Dualistic distribution coefficients of elements in the system mineral-hydrothermal solution. I. Gold accumulation in pyrite. Geochemistry, No. 6, pp. 295- 604, 2011.
[17] V.L. Tauson, R.G. Kravtsova, “Gold distribution and modes of gold occurrence of pyrites of epithermal gold-silver deposits of Northern Okhotsk region”, in Proc. II Intern. Mining and Geol. Forum Gold of North Pacific Margin, Magadan, 2011. pp. 17-19. Engl.