GEOLOGICAL CHARACTERISTICS AND PROSPECTING DIRECTION OF MOLYBDENUM POLYMETALLIC DEPOSITS IN YAKESHI REGION, INNER MONGOLIA

More than 20 molybdenum polymetallic deposits and occurrences have been discovered in Yakeshi region which is located on the southeast of Derbugan fault on the western slope of central Daxinganling Mountains and belongs to Xing'an-Mongolian metallogenic belt, showing good metallogenic conditions and great prospecting potential. Based on the regional geological and mineral survey, the types of molybdenum(Mo) polymetallic deposits are classified and the deposit genesis and prospecting direction are analyzed through comparative study of regional geological background and typical deposits. It is considered that the Mo-polymetallic deposits mainly include porphyry type, magmatic hydrothermal type, greisen type, fractured altered rock type, skarn type and porphyry-disseminated fissure filling type. The mineralization is mainly related to granite(porphyry) rock mass and fault structure. The ore-forming process is the result of the combined action of several plate movements, involving the continent-continent collision between North China Plate and Mongolia Block and the subduction of paleo-Pacific Plate towards Asiatic Plate. The discovery of Pb, Zn, Ag and Mo deposits in the area reflects the effectiveness of geochemical exploration. Therefore, the mineral exploration in the region should fully consider the coincidence degree between metallogenic geological background and 1:200 000 stream sediment geochemical anomaly, and use geological, geophysical, geochemical prospecting and GIS for accurate prediction of prospect and target areas, in order to prospect for Mesozoic porphyry and hydrothermal vein type Mo-polymetallic deposits as well as the Late Paleozoic porphyry molybdenum deposits.