Geochronology, geochemistry, Sr–Nd–Hf isotopic compositions, and petrogenetic and tectonic implications of Early Cretaceous intrusions associated with the Duolong porphyry–epithermal Cu–Au deposit, central Tibet

ABSTRACTThis article reports new zircon laser ablation-multicollector-inductively coupled plasma-mass spectrometry U–Pb and Hf isotope, whole-rock major and trace element, and Sr–Nd isotope data for mineralized and barren intrusions associated with the Duolong porphyry–epithermal copper–(gold) deposit (DPCD, a mining camp containing several individual deposits) in the western Qiangtang Terrane (QT), central Tibet. These data are used to further our understanding of the geological evolution of this region. The mineralized and barren DPCD intrusions are typical I-type granitoids that were synchronously emplaced at ca. 112.6–125.9 Ma. These igneous rocks show arc affinities that are characterized by enrichments in the light rare earth elements (LaN/YbN = 4.08–15.23) and the light ion lithophile elements (Rb, Th, U, K, and Pb), and depletions in the high field strength elements (Nb, Ta, and Ti). They have 87Sr/86Sr(i) values of 0.7046–0.7079, Nd(t) values of –6.0 to +1.1, and two-stage Nd model ages of ca. 82...