Geological setting, geological characteristics and mineralization of gold deposits in northern Finland

Gold deposits in northern Finland occur like numerous stars in Paleoproterozoic Central Lapland greenbelt (CLGB) and Kuusamo-Perapohjaschist greenbelt. Gold deposits in northern Finland can be divided into three categories: orogenic gold deposits, iron oxide Cu-Au deposits (IOCG) and placer gold deposits. Most of orogenic gold deposits are distributed mainly over CLGB and Kuusamo-Perapohjaschist greenbelt. The most common ore minerals of orogenic gold deposits are pyrite, arsenopyrite, chalcopyrite and pyrrhotite, whereas the accessory minerals are mainly galena, sphalerite and tetrahedrite. The wall rock alterations of orogenic gold deposits mainly include albitization, sericitization, biotitization, carbonatization and, to some extent, chloritization. The orogenic gold deposits have many similarities in mineralization, and main controlling factors include tectonics, lithology and orogenic metamorphism. The IOCG deposits in northern Finland are distributed mainly in the Clariant area of west CLGB, and the wall rocks are albite-anthophyllite rocks with strong wall rock alteration and obvious zonation. Elements concentrated in the ore are Ag, Au, Bi, Co, Cu, Fe, Mo, LREE, S, Se, and Te. The mineralization of IOCG deposits was closely related to magmatic hydrothermal activity and structure. Placer gold deposits in northern Finland comprise paleoplacer deposits and placer deposits which are mainly distributed in the northeast of CLGB.Gold deposits in northern Finland are of great significance for the mineral exploration in Arctic Circle and adjacent areas; on the other hand, the study of ore deposits in northern Finland is of reference value for the gold exporation work in such areas as the Jiaodong Peninsula, the northern margin of North China Craton, Xiao Qinling and Qinling area and northern Xinjiang in China.