A genetic model of PGM hosted in cumulative gabbro-pyroxenite-dunite complexes of the Koryak Highland, Russia

Platinum-group minerals from the Malaya Kamenushka River placer, Middle Urals, Russia

“…The specific features of the PGM assemblage of the Malaya Kamenushka River placer correspond to the placers of iridium-platinum mineralogical-geochemical type (Korchuganova, 2010;Mochalov, 2013), characteristic of most placers associated with Uralian-Alaskan type massifs (Cabri et al, 1996;Weiser, 2002). The extensive development of the Os-Ir-Ru mineral inclusions and PGE sulfides is a characteristic feature of the PGM assemblage of the Malaya Kamenushka River placer.…”

“…The characteristics of the lode sources of these placers – Uralian–Alaskan type massifs or zonal clinopyroxene–dunite massifs are discussed in numerous publications (Zavaritsky, 1928; Betekhtin, 1935; Lazarenkov et al ., 1992; Ivanov, 1997; Garuti et al , 2003; Auge et al , 2005; Tolstykh et al , 2011; Stepanov et al , 2015; Malitch et al , 2017; Stepanov et al , 2017; Palamarchuk et al , 2017a; 2017b; Stepanov et al , 2018). In contrast, the features of the PGM of the Ural platinum belt have been significantly less studied (Barannikov and Osovetsky, 2014) than, for example, the Koryak–Kamchatka belt (Tolstykh et al , 2000; Sidorov et al , 2004; Tolstykh et al , 2004; Mochalov, 2013; Kutyrev et al , 2018; Sidorov et al , 2019) and other regions of the World (Cabri et al 1981; Johan et al , 1990; Nixon et al , 1990; Slansky et al , 1991; Cabri et al , 1996; Johan et al , 2000; Tolstykh et al , 2002; Weiser, 2002).…”

Experimental Study of Pt Solubility in the CO-CO2 Fluid at Low fO2 and Subsolidus Conditions of the Ultramafic-Mafic Intrusions

“…Some investigators attributed the formation of Pt-Fe alloys to the magmatic stage of evolution of gabbro-pyroxenite-dunite massifs (e.g., [45,46]). Karpinsky in 1926 (see in [1]) proposed metasomatic mechanism of formation of chromitite-Pt association as a result of interaction of dunite with fluid containing Cr and Pt. Some modern researchers are developing similar models of the interaction cumulus-fluid as a mechanism of PGE localization [1,47].…”

“…Karpinsky in 1926 (see in [1]) proposed metasomatic mechanism of formation of chromitite-Pt association as a result of interaction of dunite with fluid containing Cr and Pt. Some modern researchers are developing similar models of the interaction cumulus-fluid as a mechanism of PGE localization [1,47].…”

“…At conditions of high oxygen fugacity (f O2 ) in the basic magmas of the subduction zones, no sulfides are formed and PGE are disseminated in the intrusive rocks. In the Ural-Alaska concentric intrusions of subduction origin, PGE are mobilized and concentrated at the post-magmatic stage as a result of the high-temperature fluid-rock interaction [1]. Postmagmatic fluid is also involved in the formation of the low sulphide type PGE deposits of Merensky reef type in the layered ultramafic-mafic intrusions with sulfide mineralization (Bushveld, SA and other) [2].…”