Magmatic Evolution And Metallogenic Prediction Of South Wengen Mafic-ultramafic Complex, Inner Mongolia

South Wengen mafic-ultramafic Complex is located in the western section of north edge of Sino-Korea Platform, which is close to the geosyncline-platform boundary. Mafic-ultramafic intrusion invaded in metaquartzite in Shujigou formation of Zha’er-taishan group.The U-Pb isotopic age is about 280Ma,which is belong to early stage of Permian Main rock types are dunite,wehrlite,troctolite,olivine gabbro,ferrogabbro and gabbro.Petrogenetic minerals are chrysolite, endiopside,bytownite,anorthite and hornblende. The whole rock show high MgO and low SiO2、K2O+Na2O and TiO₂. REE character-ristics show light REE mid-rich, sharp Eu and Tm positive anomaly. In spider diagram, it is strongly enriched in Pb, Sr and lightly depleted in Nb, Ta, Ti. The composition of primitive magma is estimated to MgO=11.73%, FeO=11.38% , belonging to high-Mg basaltic magma. Ni sulfide mineralization beening founded mineral bearing Ni is pentlandite and pyrrhotite within wehrlite and troctolite. The textures of ores are massive net and disseminated.In the processes of mafic-ultramafic magma evolution,Wengen South rock had sulfide liquid differentiation. In the meantime, the quality of Wengen South ore magma is close to Voisey’s Bay. So it is possibly to exist Cu-Ni deposit.