Discovery of a Large-scale Porphyry Molybdenum Deposit in Tibet through a Modified TEM Exploration Method

Abstract

During the last decade, there have been many exploration achievements in the Tibetan Gangdese metallogenic belt. The Sharang area of the Tibetan region is covered by a low-temperature mineralized alterable clay that is considered to be a low-grade ore. Although small intervals of rich molybdenum (Mo) mineralization have been discovered, the ore deposit scale is limited and the condition of deep ore is still unknown. To explore these deeper targets, a modified large-loop TEM system was used in the Sharang area. The TEM receiver configuration is redesigned and the late-time resistivity equation of large-loop TEM has also been defined. During data processing, two regions with low resistivity anomalies were discovered. The interpreted results indicate that the main ore deposit is buried 200 m beneath the surface, and extends 600 m vertically. The total anomalous area associated with the ore deposit is estimated at 3.77 km2. The interpretation results are consistent with drilling data acquired after the geophysical survey. The results show that it is the first ultra-large porphyry molybdenum deposit that has been found in Tibet.