Early Mesozoic tectono-magmatic activity and mineralization in northeast China: Evidence from Re-Os to U-Pb studies of the Taipingchuan porphyry Cu-Mo deposit in the Derbugan metallogenic belt

Abstract

The Taipingchuan Cu-Mo deposit is a recently discovered large porphyry deposit located in the north of the Derbugan metallogenic belt of northeastern China. The geochronological data of the deposit yielded a Late Triassic zircon U-Pb age of 202 ± 6 Ma from a granodiorite porphyry that hosts the Cu-Mo mineralization. Measured Re-Os isotopes of seven disseminated molybdenite samples yielded an isochron age of 200 ± 5 Ma with mean square of weighted deviates of 2.7, while those of seven veinlet molybdenite samples also produced an isochron age of 200.1 ± 2.5 Ma and mean square of weighted deviates of 3.3. These isochron ages show that a Cu-Mo mineralization event occurred at ca. 200 Ma. Based on regional tectonic evolution, we propose that the Late Triassic Cu-Mo mineralization of the host porphyry in the Derbugan metallogenic belt was mainly associated with the subduction of the Mongol-Okhotsk Ocean slab under the Ergun block, contrary to previous suggestion that it was related to the subduction of the Mesozoic Palaeo-Pacific plate. © 2014 Taylor & Francis.