Trace-Element Geochemistry of Molybdenite from Porphyry Cu Deposits of the Birgilda-Tomino Ore Cluster (South Urals, Russia)
Mineralogical Magazine, May 2018, Vol. 82(S1), pp. S281–S306 Trace-element geochemistry of molybdenite from porphyry Cu deposits of the Birgilda-Tomino ore cluster (South Urals, Russia) 1,* 1 1,2 3 OLGA Y. P LOTINSKAYA ,VERA D. ABRAMOVA ,ELENA O. GROZNOVA ,SVETLANA G. TESSALINA , 4 4 REIMAR SELTMANN AND JOHN SPRATT 1 Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry Russian Academy of Sciences (IGEM RAS), Staromonetny per. 35, Moscow 119017, Russia 2 Institute of Experimental Mineralogy Russian Academy of Sciences (IEM RAS), Chernogolovka, Moscow region 142432, Russia 3 John de Laeter Centre for Isotope Research & The Institute for Geoscience Research (TIGeR), Curtin University, Kent St, Bentley, WA 6102, Australia 4 Natural History Museum, London SW7 5BD, UK [Received 16 January 2017; Accepted 23 December 2017; Associate Editor: Krister Sundblad] ABSTRACT Mineralogical, electron microprobe analysis and laser ablation-inductively coupled plasma-mass spectrometry data from molybdenite within two porphyry copper deposits (Kalinovskoe and Birgilda) of the Birgilda-Tomino ore cluster (South Urals) are presented.† The results provide evidence that molybdenites from these two sites have similar trace-element chemistry. Most trace elements (Si, Fe, Co, Cu, Zn, Ag, Sb, Te, Pb, Bi, Au, As and Se) form mineral inclusions within molybdenite. The Re contents in molybdenite vary from 8.7 ppm to 1.13 wt.%. The Re distribution within single molybdenite flakes is always extremely heterogeneous. It is argued that a temperature decrease favours the formation of Re-rich molybdenite. The high Re content of molybdenite observed points to a mantle-derived source. K EYWORDS: molybdenite, LA-ICP-MS, porphyry copper deposits, Urals.
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