LA-ICP-MS zircon U-Pb dating of granodiorite porphyry in the Lianhuashan copper deposit of Inner Mongolia and its geological implications

On the basis of previous studies, this paper carried out zircon U-Pb dating for mineralization-associated granodiorite porphyry to further study its metallogenic epoch. Four groups of ages were obtained. The first group contains one zircon with 206Pb/238U age of 343Ma±2Ma; the second group contains one zircon with 206Pb/238U age of 264Ma±2Ma; the third group contains one zircon with 206Pb/238U age of 256Ma±2Ma; the fourth group comprises 17 zircons, whose 206Pb/238U ages vary from 240Ma to 249Ma, with a weighted mean 206Pb/238U age of 246.4Ma±1.2Ma (N=17). In conjunction with characteristics of CL imaging, the authors hold that the emplacement of granodiorite porphyry occurred between the Late Permian and Early Triassic.