Fluid regime of formation of the Loipishnyun low-sulfide PGE deposit, Monchetundra basic massif (Kola Peninsula, Russia)

Abstract

The distribution features of the volatile components (H2O, H2, CO2, CO, H2S, SO2, CH4 and N2) was investigated by method of pyrolytic gas chromatography in the ore-free and ore-bearing rocks of the low-sulfide PGE deposit Loipishnyun of the basal structural type, which localized within Monchetundra mafic massif of the Kola region. It was established that PGE ore, compared with the ore-free rocks are higher overall fluid-saturated, higher contents of H2O and especially H2S and SO2. In the ore-free rocks, in contrast to the mineralized one, was revealed higher concentrations of CO, H2 and N2. H2S and SO2 play the main role to the process of the platinum-metal ore formation. The contribution of these components at the initial stage of the platinum-metal ore genesis is equivalent, as evidenced by the close values of positive correlations of these volatile compounds with platinum group metals and ore elements. With further decrease of temperature in the process of the ore genesis are dominate by the hydrogen sulfide, which has a high positive correlation mainly with copper and platinum group metals. The obtained results suggest that the process of the platinum-metal ore genesis proceeded in a wide temperature range from 1050 to 450°C. It began in late-magmatic, postcumulus stage (1050-850°C) under variable redox conditions and continued with the gradual reduction of the temperature to 450°C in conditions decreasing sulfur fugasity.

Keywords

• летучие компоненты
• пиролизная газовая хроматография
• флюидный режим
• платинометалльное оруденение
• месторождение лойпишнюн
• мончетундровский массив
• volatile components
• pyrolysis gas chromatography
• fluid regime
• pge mineralization
• loipishnyun deposit
• monchetundra massif