Gold-Platinoid Mineralization of Metasomatically Altered Ultramafites in Precambrian Protrusions of Mamynsky Geoblok

On the contiguous territories of Russia and Chi-na,along the left and right banks of the Amur Riv-er (Heilongjiang Province of China,and Amur Oblast' of Russia),among the Late Mesozoic ter-rigenous and volcano-plutonic formations,several Precambrian prot…

Gold-Platinoid Mineralization of Metasomatically Altered Ultramafites in Precambrian Protrusions of Mamynsky Geoblok

On the contiguous territories of Russia and China, along the left and right banks of the Amur River (Heilongjiang Province of China, and Amur Oblast' of Russia), several Precambrian protrusions (Gonzhinsk, Mamynsk, Amurkhe, and Khumakhe) are known. On the Russian territory, along the setting and on the area of the protrusions, lode manifestations, precious-metal deposits, and gold-platinoid placers are known having the industrial importance. Ultramafites are metasomatically altered more likely by the action of the Late Paleozoic intrusions and produced by them hydrothermae, and are transformed into listvenites. It can be concluded that as one of the sources of precious metals in the placers were the aureoles of listvenitization. This is evidenced by the presence of talc (typomorphic mineral of apoultrabasites) inclusions together with Pt-, Pd- and Ir-bearing gold in the corrosive coatings of the primary platinoids. This conclusion requires the revision of the work strategy of prospecting the lode gold and PGE manifestations within the ore-placer node because apoultrabasites before were considered non-promising for precious metals.