GEOLOGY AND GEODYNAMIC SETTING OF THE CONCEALED PORPHYRY MOLYBDENUM DEPOSIT IN YAOCHONG, HENAN PROVINCE

With comprehensive analysis and comparative study on the metallogenic setting, occurrence characteristics, metallogenic epoch and geodynamic setting of the Yaochong concealed porphyry Mo deposit, it is concluded that the Yaochong Mo deposit occurs in the western section of Dabie metallogenic belt, with the orebody hosted in the Mesoproterozoic altered gneiss at the exocontact of granite-porphyry body (dyke) and controlled by concealed porphyry and structures. The deposit is formed mainly by filling mineralization. The main molybdenite mineralization occurs in dissemination, veinlet-stockwork, thin film and breccia. With former researches on the northern foot of Dabie Mountains and the isotopic age contrast between Yaochong Mo deposit and neighboring Mo deposits, ore-bearing porphyry and Mesozoic granite batholiths, the authors suppose that the metallogenic age of the Yaochong Mo deposit is about 140 Ma and the corresponding geodynamic setting is the rapid lithospheric thinning on a large scale in Eastern China.