Zircon SHRIMP U-Pb dating of the Jingren granite, Yemaquan region of the east Kunlun and its geological significance

Yemaquan region in western part of the East Kunlun Range (the Qimantage) is one of the most important metallogenic districts in Qinghai Province. Many granitoid-related iron, copper and polymetallic deposits have recently been discovered during regional geological investigations. This paper presents new zircon SHRIMP U-Pb dating and geochemical data of Jingren syenogranite, which shows a close relationship to polymetallic mineralization and geochemical affinity with late-post orogenic granites. The SHRIMP U-Pb dating yields an age of 204.1 +/- 2.6Ma for the syenogranite intrusion. This age tells us that the major tectonomagmatic epoch for western part of the East Kunlun Orogenic Belt is of late Paleozoic early Mesozoic (Variscian-Indochina) epoch,which is similar to the eastern part of the East Kunlun Orogenic Belt. Furthermore, the SHRIMP U-Pb dating of Jingren syenogranite, together with other updated isotope geochronology data indicate that the major epoch of iron, copper and polymetallic mineralization is of the late Indo-Chinese epoch, namely, the late stage of the major tectonomagmatic cycle, for western part of the East Kunlun. Therefore, the potential prospecting targets in this region should be the late Indo-Chinese granite plutons and related polymetallic mineralization.