内蒙古牙克石地区钼多金属矿床地质特征及找矿方向

牙克石地区位于大兴安岭中段西坡得尔布干断裂的南东侧,隶属于兴-蒙成矿带,已发现钼多金属矿床(点)20余处,显示了较好的成矿条件及巨大的找矿潜力. 在区域地质矿产调查的基础上,通过对区域地质背景及典型矿床的对比分析,划分了钼多金属矿床的类型,分析了矿床的成因及找矿方向. 研究认为区域钼多金属矿床主要有斑岩型、岩浆热液型、云英岩型、破碎带蚀变岩型、夕卡岩型、细脉浸染裂隙充填型,成矿多与花岗(斑)岩体及断裂构造有关,成矿过程与华北板块与蒙古地块的陆-陆碰撞和古太平洋板块向亚洲板块俯冲有关,是多个板块运动联合作用的产物. 研究区内铅锌银钼矿的发现,体现了化探工作找矿的有效性. 因此,在该地区进行矿产勘查工作,应充分考虑成矿地质背景和1:20万水系沉积物地球化学异常的吻合程度,利用地质、物探、化探、GIS技术精准预测远景区及靶区,以期寻找中生代斑岩型和热液脉型钼多金属矿床,兼顾晚古生代斑岩型钼矿.

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.