Zircon SHRIMP U-Pb age of intermediate-acid intrusive rocks in Kaladawan area, eastern Altun Mountains, NW China, and its implications
阿尔金山喀腊大湾地区中酸性侵入岩SHRIMP年龄及其意义

Kaladawan area of eastern Altun Mountains,is tectonically sandwiched between NE-trending Altun strike-slip fault and EW-trending northern Altun marginal fault.There outcropping a series of intermediate-acid intrusive rocks which were determined as Late Paleozoic era.In this paper,the authors for the first time take measurements of SHRIMP U-Pb zircon age of the intermediate-acid intrusive rocks and give a high quality age of 413～514Ma.The results reflect that there happened a series strong magmatic intrusive activity in Early Paleozoic era.With other dating data of the intrusive rocks by other methods in the area and with SHRIMP U-Pb zircon age of the intermediate-acid intrusive and ophiolite in Hongliugou area about 180km to the west of Kaladawan area,the magmatic intrusive activity in Kaladawan area of eastern Altun Mountains can be divide to three stage as follows:pre-collision(520～500Ma),syn-collision(490～470Ma)and post-collision(440～410Ma).