Zircon LA-ICP-MS U-Pb age of plagiogranite porphyry in the Cunqian copper polymetallic deposit of Jiangxi Province and its geological implications

Abstract：The Cunqian copper polymetallic deposit is an important porphyry-skarn deposit along eastern Qinhang metallogenic belt. The ore-bearing intrusive body comprises biotite plagiogranite porphyry and plagiogranite porphyry, characterized by repeated invasion and calcium-basic rocks. The LA-ICP-MS technique was used in this study, and U-Th-Pb isotopic analysis was made for zircons from the ore-bearing plagioclase granite porphyry, with the petrogenic age obtained being (169.3 ± 1.1)Ma. This petrogenic age of the ore-bearing rock body is very close to ages of Dexing granodiorite porphyry, Yinshan quartz porphyry, Lengshuikeng granite porphyry and Tongcun granite-porphyry, suggesting that an event of large-scale magmatic emplacement and mineralization took place in 175-156Ma, which led to the formation of many porphyry-skarn copper polymetallic deposits related to adakite or alkali-calcic granite, and implying that the Qinhang metallogenic belt produced a metallogenic series of porphyry-skarn copper polymetallic deposits under the same magma-dynamic background in this period.