Zircon LA-ICP-MS U-Pb age of the Zalaga porphyry associated with Cu-Mo mineralization in the Yulong ore belt and its geological implication
HE Guo-chao;WANG Guang-qiang;HUANG Wen-ting;ZOU Yin-qiao;WU Jing;LIANG Hua-ying;ZHANG Yu-quan;Charllote M ALLEN;Resource Exploration Co. Ltd of Guangxi Non-Ferrous Metal Group Co.,Ltd;Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences;University of Chinese Academy of Sciences;Research School of Earth Sciences, Australian National University;
The Zalaga porphyry Cu-Mo deposit is located at the northern domain of the Yulong porphyry copper ore belt in the eastern Tibet. The porphyry emplaced into the lower Permian volcanic rock and Late Triassic sandstone and could be divided into early stage monzonite granite porphyry and late stage syenogranite porphyry. Both stages of the porphyry were dated, respectively, using zircon LA-ICP-MS U-Pb method. The early stage monzonite granite porphyry has zircon LA-ICP-MS U-Pb age of(38.5±0.2) Ma, MSWD=1.12 and the late stage syenogranite porphyry has zircon LA-ICP-MS U-Pb age of(38.5±0.2) Ma, MSWD=1.08. The early porphyry has the same zircon LA-ICP-MS U-Pb age as that of the late stage porphyry, suggesting that the early porphyry and late stage porphyry emplaced almost at the same time and that the Zalaga porphyry was emplaced during the Late Eocene. Based on the structural condition of the period during Eocene to Oligocene in eastern Tibet, it is concluded that the Zalaga porphyry Cu-Mo(Au) deposit and the Yulong porphyry copper ore belt has genetic relation to the activities of strike-slip fault zone which transverses the lithosphere mantle and triggered the magmatic activities caused by the collision between Indian and Asia continents.