Geological and geochemical characteristics and metallogenic model of the Wenquan molybdenum deposit

The Wenquan molybdenum deposit is a kind of large-sized porphyry molybdenum deposit found in recent years. In this paper, on the basis of deposit geology, geochemistry and isotope geochronology data, the metallogenic model of this deposit was established. The Wenquan granitic batholith belongs to the K-rich (alkali-rich) calc-alkaline rock series, which is the mineralization parent rock. The rock massif shows the characteristics of both crust-remelting granite and mantle-source granite. At the same time, the data of REE contents, hydrogen and oxygen isotopes and inclusion temperatures showed that the metallogenic hydrothermal solution is a mixed mesothermal solution of magmato-hydrothermal fluid and meteoric water. Mineralization was dated at 214±7.1 Ma, basically identical with the parent rock's age (207-226 Ma). This reflects that molybdenum mineralization has a close relation to tectonic magmatism evoked by orogenic processes, and molybdenum mineralization occurred mainly at the petrogenesis stage at the late stage of magma emplacement. Mixing with meteoric water led to a decrease in the salinity of magmato-hydrothermal solution and changes in other physical and chemical properties. During the tectonic process, ore-bearing hydrothermal solution ascended along favorable fault structure channels. With physicochemical changes, it filled in the surrounding rock joints on both sides of faults, forming ore deposits. © 2011 Science Press, Institute of Geochemistry, CAS and Springer-Verlag Berlin Heidelberg.