Yanshanian magmatism and gold-polymetallic mineralization dynamics in northeastern Shanxi Province, China
晋东北燕山期岩浆活动与金多金属成矿作用动力学

The Yanshanian magmatism in the northeastern part of the Shanxi Province, controlled by regional structures, occurred as northeast belt with local concentrations. These magmatic rocks, formed in three pulses at 150~160Ma, 130~140Ma and 85~127Ma, can be grouped into two suits. The former suit is comprised of granodiorite, monzongranite and coarse grain porphyritic biotite granite. The later suit is composed of diorite, granodiorite porphyry, granitic porphyry and quartz porphyry. The later suit shows close relationship to gold and basic sulfide mineralization. Most of these magmatic rocks are peraluminous and alkaline rocks with adakite affinity. These rocks belong to I-type and were evolved from same source. The formation of these granitic rocks was probably related to crust-mantle interaction triggered by lithosphere thinning of the North China Craton in Mesozoic. Related to the Yanshanian magmatic activities, mineral deposits also show concentration and multi-stage mineralization. The mineral deposit types include porphyritic Mo-Au, skarn-hydrothermal vein Au, Fe, and explosive breccia-hydrothermal quartz vein type Au or Cu-Ag, Ag-Pb-Zn deposit. Some of these types were overlapped sometimes in the same area and show spatial zone in elemental distributions. The Mo-Au mineralization was in 150~160Ma and is related to the monzondiorite or quartz diorite, granodiorite. The Au mineralization was in 130~140Ma, and is related to quartz diorite and quartz porphyry. Ag and basic sulfide mineralization were in 85~127Ma, and is related to granitic porphyry, quartz porphyry and explosive breccia rocks. Hydrothermal fluid responsible for this mineralization was soured from related magmatic activity. These metallic mineralization were genetically related to the tectonic regime transition of North China Craton in Mesozoic, lithosphere thinning, and inner land orogenesis and large scale magmatic activities.