Geochronology, petrogenesis and tectonic significance of Huashugou granitoids in North Qilian, NW China

摘要

North Qilian Orogenic Belt (NQOB) is a typical early Paleozoic orogenic belt in China. However, the tectonic setting of NQOB remains controversial, especially the post-subduction processes. In this study, we report whole-rock geochemistry, zircon U–Pb ages, and Hf–Nd isotopic compositions of Huashugou granitoids in the western segment of the NQOB, NW China. LA-ICP-MS U–Pb dating of zircon from Huashugou granitoids indicate magmatic crystallization ages of ca. 420?Ma, with late-Paleoproterozoic captured zircons of ca. 1700?Ma. The Huashugou granitoids show enrichment in light rare earth elements and large-ion lithophile elements (e.g., Rb, Th and U), depletion of heavy rare earth elements and high-field-strength elements (e.g., Nb, Ta and Ti), negative Eu anomalies, and A/CNK?