Geologicheskii Vestnik

We present some results of study of mineralogical peculiarities of chromitites from serpentinite mélange zone in the eastern part of Nurali massif.It wasfound that chromian spinel grainsfrom Sherambayskoe and Sarusakkul area occurrences are high-Cr as those from chromitite bodies of the inner parts of ophiolite mantle section. The main accessory minerals in the chromitite are Ni-sulfides and arsenides (millerite, heazlewoodite and orcelite). These often enclose tiny precipitations (1–7 μm) of platinum group minerals (PGM). Chemically, this mineralizations belong to a mixed type with Os, Pt, Ir>Ru>Pd, Rh. We infer that accessory minerals formation including PGM was caused by both tectonic redistribution of matter and interaction of chromitites with low-T fluids.

ultramafic rock, chromian spinel, accessory minerals, base metal sulfides, PGE, Nurali massif

• Dmitrenko G.G., Gorelova E.M., Savelieva G.N. Platinum group minerals in chromites of the Nurali massif (the Southern Urals) // Doklady Earth Sci. 1992. V. 324. P. 403–406.
• Grieco G., Diella V., Chaplygina N.L., Savelieva G.N. Platinum group elements zoning and mineralogy of chromitites from the cumulate sequence of the Nurali massif (Southern Urals, Russia) // Ore Geol. Reviews. 2007. V. 30. P. 257–276. doi.org/10.1016/j.oregeorev.2006.03.002.
• Moloshag V.P., Smirnov S.V. Platinoidnaya mineralizatsiya Nuralinskogo giperbazit-gabbrovogo massiva (Yuzhnyi Ural) [PGE mineralization of the Nurali ultramafic-gabbroic massif (the South Urals)] // Zapiski RMO. 1996. V. 1. P. 48–54 (in Russian).
• Saveliev D.E., Ankusheva N.N. Nurali ophiolite massif (the Southern Urals): geological, structural and mineralogical features // Bulletin of Perm University. Geology. 2018. V. 18 (3). P. 230–253. doi.org/10.17072/psu.geol.17.3.228.
• Saveliev D.E., Zaykov V.V., Kotlyarov V.A., Zaykova E.V., Kraynev Yu.D. Khromshpinelidy i aktsessornaya mineralizatsiya v khromititakh i ul’tramafitakh Nuralinskogo massiva (Yuzhnyi Ural) [Chromespinelides and accessory mineralization in chromitites and Ultramafites of the Nurali massif, Southern Urals] // Zapiski RMO. 2017. V. 1. P. 59–83 (in Russian).
• Smirnov S.V. Petrologiya verlit-klinopiroksenit-gabbrovoi assotsiatsii Nuralinskogo giperbazitovogo massiva i svyazannoe s nim platinoidnoe orudenenie [Petrology of the wehrliteclinopyroxenite-gabbro association of the Nurali ultrabasite massif and associated PGE mineralization]: PhD thesis syn. Ekaterinburg: IGG UB RAS, 1995. 18 p. (in Russian).
• Zaccarini F., Pushkarev E.V., Fershtater G.B., Garuti G. Composition and mineralogy of PGE-rich chromitites in the Nurali Lherzolite-gabbro complex // Canadian Mineralogist. 2004. V. 42. P. 545–562. doi.org/10.2113/gscanmin.42.2.545.
• Zaykov V.V., Melekestzeva I.Yu., Kotlyarov V.A., Zaykova E.V., Kraynev Yu.D. Srostki mineralovEPG v Miasskoirossypnoi zone i ikh korennye istochniki [Intergrowths of platinum group minerals from the Miass placer zone (the Southern Urals) and their primary sources] // Mineralogiya. 2016. V. 4. P. 31–47 (in Russian).