Abstract:

Due to much covering by sand and grass, there is less mineralization information on the ground in Daolangheduge tungsten-polymetallic mine. Geological and geochemical studies show that the Early Cretaceous K-feldspar granite closely correlates to tungsten mineralization, while the orehosting rock is chiefly the Permian augite diorite. According to the difference of physical property between host rock and ore body, the geological mapping, magnetic and gravity survey at scale of 1∶10 000 have been completed in the deposit. By integrated gravity-magnetic inversions of data, three NE-trending important structural alteration zones are identified in augite diorite occurring in the northwestern part of the deposit, which correspond to negative magnetic anomalies, respectively. Parallel to the boundary between augite diorite and K-feldspar granite, the three zones have the length of 800-3 000 m and the width of 50-100 m. As a result, six integrated geophysical anomalies are predicted in augite diorite. The depth of anomalies does not exceed 1 000 m and the area of a single anomaly is usually 500 800 m². Through drilling, three blinded fractured-zone type tungsten-polymetallic exploration targets are discovered.  Tungsten-polymetallic  ore bodies are sited in the depth of 150-650 m. The thickness of the ore body is 2-4 m. The combination method of regional metallogenic condition analysis and integrated gravity-magnetic inversions is confirmed to be effective for forecasting tungsten deposit in covered area and worth to being applied in other region.

Key words: covered area, tungsten-polymetallic deposit, magnetism, gravitation, integrated positioning forecasting