中文摘要：

金水口岩体出露于东昆仑北坡，岩性主要为含石榴子石的过铝花岗岩和不含石榴子石的二长花岗岩及花岗闪长岩。自该岩体从金水口群解体以来，其形成时代一直制约着该地区构造演化的恢复。对锆石内部结构、阴极发光图像特征和Th／U比值的研究表明，金水口岩体中锆石主要为岩浆锆石，个别含有残留锆石核。锆石U-Pb同位素LA-ICPMS和SHRIMP原位分析结果显示，金水口电站周围的石榴堇青花岗岩及黑云母花岗闪长岩形成年龄分别为（411±17）Ma和（396±18）Ma，说明金水口岩体为早泥盆世的花岗质侵入体，是在早古生代末由柴达木地块基底富Si和Al的地壳物质重熔的产物。该套S型花岗岩记录了古元古代的两期源区物质信息（约1．63Ga和约1．78Ga），代表了东昆仑造山带早古生代末期的一期重要岩浆热事件。

英文摘要：

The Jinshuikou pluton, intruding into the Jinshuikou Group low north slope of East Kunlun Mountains. This pluton mainly consists of granod bearing peraluminous granite. Although reconstruction of their tectonic evolution metamorphic rocks, is located in the iorite, monzonitic granite and garnetthe ages of these granitoids and their tectonic environment are crucial to the in this area, lack of enough accurate and reliable geochronological data for this pluton has made such an effort less successful. The internal structures, Th/U ratios of the zircon grains from these granitoids reveal that these zircon grains have typical （CL） images and characteristics of magmatic zircon except for some zircon grains with residual cores. The LA-ICPMS and SHRIMP analyses show that the zircon grains from the garnet cordierite granite and biotite granodiorite near the Jinshuikou powerstation have concordant U-Pb ages of （411±17） Ma and （396±18） Ma, respectively. These data indicate that the Jinshuikou pluton is a granitic intrusion formed in Early Devonian, and it was probably derived from partial melting of crustal materials equivalent to the basement of Qaidam Terrain in late Early Paleozoic. Moreover, detrital zircons of 1.63 Ga and 1.78 Ga are found in the S-type granite pluton, indicating significant Paleoproterozoic materials in the source.