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The genesis of the rare-metal greisen Tigrinoe ore-deposit (Sikhote-Alin, Russia): Sm-Nd and Rb-Sr isotope constraints
Published in Adam Piestrzyński, Mineral Deposits at the Beginning of the 21st Century, 2001
R. S. Krymsky, B. V. Belyatsky, A. K. Rub, M. G. Rub
One of the most important goals of economic geology is to find out the connection between granite formation and ore mineralization. For a long time it was generally accepted that the processes of greisen and vein formation which are directly coincided with W-Sn ore mineralization and strictly connected with the last stages of crystallization of granite intrusions and origination of residual magmatic fluid. At this W and Sn have to be taken out of granite melt, store within residual fluid and deposit in greisen-vein zones of apical parts of intrusions or directly above them. Our study of Sm-Nd and Rb-Sr systematics of some rare-metal granites and their tin and tungsten ore-deposits of Far East of Russia encounters the cases of this time span (Belyatsky et al., 1994; Krymsky et al., 1997). Also we pointed to significant participation of mantle material in formation of this granites and ore-bearing veins. The Tigrinoe ore-deposit was chosen for detail investigation as a typical greisen Sn-W ore-deposit, which is supposed to be connected with typical Li-F rare-metal granites. The main goal of this work was to decipher the time- and genetic relations between ore vein mineralization and host granites.
Metamorphic Rocks
Published in F.G.H. Blyth, M. H. de Freitas, A Geology for Engineers, 2017
F.G.H. Blyth, M. H. de Freitas
Composed essentially of quartz, white mica, and accessory amounts of tourmaline, fluorite, and topaz, this is formed from granite under certain pneumatolytic conditions; where, for example, the formation of K2CO3 in the above equation is inhibited, white mica (secondary muscovite) is formed from the feldspar of the granite and the name greisen is given to the resulting rock.
Cretaceous tungsten-tin mineralisation in the Tin Range, Stewart Island, New Zealand
Published in New Zealand Journal of Geology and Geophysics, 2022
Hamish C. Lilley, James M. Scott, Josh J. Schwartz, Rose E. Turnbull, Andy J. Tulloch
Tungsten-tin (W-Sn) mineralisation associated with granitoid magmas has been an important source of Sn throughout much of human history with, for example, Bronze Age mining of Sn from greisens in the Taurus Mountains (Turkey) having occurred as early as 4000 Ka (Öztürk and Hanilçi 2009; Yener et al. 1989). A greisen is a type of system that forms at the late-stage of a cooling granitic body in which exsolved fluids enriched in volatile elements, typically F-Cl-Li-B, react with aluminosilicate-rich host rocks (Černý et al. 2005). Such greisenising fluids have high K+, H+, and Na+ activities, which result in metasomatic and/or pneumatolytic reactions that breakdown earlier-formed biotite and feldspar (Černý et al. 2005). Greisenising fluids and reactions are conducive to the concentration and precipitation of high-grade W-Sn ores, usually hosted within wolframite ((Fe,Mn)WO4) and cassiterite (SnO2), and many of the world’s W-Sn deposits have formed in such a system (e.g. Cornwall, England, Panasqueira, Portugal, and the Nanling Range, South China; Pirajno 2009; Xiong et al. 2020). Typically associated mineralogies can contain quartz-fluorite-tourmaline-sericite-apatite-rutile (Černý et al. 2005). To this day greisens are key deposit types for global W-Sn production, with modern-day examples being identified on every continent except Antarctica (Romer and Kroner 2016). Both W and Sn play important roles in the modern world, mostly as industrial additives (Chakhmouradian et al. 2015; Emsley 2001).