The intermediate-acid intrusive magmatism and its geodynamic significance in Eastern Tianshan region

The intrusive magmatism of the midlater Hercynian granitoids is very strong in the Eastern Tian shan region,where the distribution of the Caledonian,the earlier Hercynian and the Indo-China granitoids arera rerelatively. The granitoids in the Eastern Tian shan region are divided in to two belts including Kangurtag-Harlik is land arc granite belt(the northern belt)and Aqishan-Yaman suisland arc belt(the southern belt). Except the Harlik Mounta in having several alka line granite plutons,the granitoids in the Eastern Tianshan region belong to the calc-alka line series. From the Caledonian period to the Indo-China period,the in trusive magma tism had undergone the six evolutional stages:preplate collision,volcanic arc,syn-collision,exten sion with in plate,orogenesis with in continent and anorogenesis. The genetic types of the Eastern Tian shan granitoids can bedivided in to M,CM,C and A types. The collision and the closing of the Southern is land a rc and the Northern island arc present prog ressive evolution from the northeast to the southwest.The copper,molybdenum and goldo redeposits such as Tuwu,Yandong,Chihu,Shiying tan,Weiquan,Baishan et al are bound up with the CM type of the a luminium supersatu rated calc-alka line granitoids.