LI Ya-zhi1,2, KONG Hui-lei1,2, LI Jin-chao1,2, JIA Qun-zi1,2, WANG Jia-you3, Namhka Norbu1,2
1. Xi'an geological survey center, CGS, Xi'an 710054, China;
2. MLR Key Laboratory of Genesis and Exploration of Magmatic Ore Deposits, Xi'an 710054, China;
3. Qinghai No. 1 Academy of Geology and Mineral Exploration, Xining 810600, China
Abstract: To clarify the forming age of the Yueliangwan plagiogranite, the LA-ICP-MS was used to measure zircon U-Pb date. The results showed that the plagiogranite was formed at 244.3±1.1Ma, Early Triassic, Indosinian period. Detailed petrological and geochemical studies indicated that the Yueliangwan plagiogranite belongs to the metaluminous calc-alkaline series with SiO2 contents of 63.89%~67.03%, (K2O+Na2O)<7.0%, K2O/Na2O=0.65-0.99, aluminum saturation index (ACNK)=0.95-0.98. The total content of REEs of the plagiogranite varied from 87.06×10-6 to 201.89×10-6 and the plagiogranite showed a right-wing distribution curve of strongly enriching LREE and negative Eu anomaly (δEu=0.66-0.76). Rb/Sr reflected the characteristics of mantle-derived magma. Tectonic discrimination diagrams showed that the Yueliangwan plagiogranite resulted from the island arc setting in the oceanic crust subduction orogenic stage.
Keywords: geochemistry LA-ICP-MS zircon U-Pb dating tectonic setting Yueliangwan plagiogranite East Kunlun
*Corresponding Author, E-Mail: liyazhi2005@163.com
Bulletin of Mineralogy, Petrology and Geochemistry Vol. 34, No.2, 2015, page 401-409
