The Granitoids Magmatism and Mineralization in West Section of the Western Qinling, NW China

Based on petrogeochemistry,the samples form intrusions in western Qiniing mostly belong to high-K talc-alkalic series with a few scatter to talc-alkalic series.The study results in this essay also show that there exist adakite and Himalaya type granites in the northern edge of Western Qinling,and the Jianglugou,Ayishan and Zhongchuan intrusions are similar to Himalaya type granite,and Ayishan pluton is similar to adakite based on the content of Sr and Yb.Whereas,the Wenquan intrusion shows both adakite and Himalaya type granite according go geochemical features.The granites of adakite and Himalaly type with low Mgx may caused by partial melting of basalts in thickened lower crust.On the other hand,the adakite and Himalaya type granitoids in the northern edge of Western Qiling provide the clue to the cofiision of subduction between the North China Plate and the Yangtze Plate in Trassic period,which lead to the event of crust thickening,and the partial melting of thickened lower curst in different depth produced adakite or Himalaya type granite.In addition,the adakite or Himalaya type granitoid in northern edge of Western Qinling should be pay more attention to the mineralization of Cu-Au.