内蒙古鄂温克旗那干楚银铜多金属勘查区成矿特征与找矿预测

Ore-forming characteristics and prospecting prediction of Naganchu Ag—Cu polymetallic exploration area in Ewenke Banner,Inner Mongolia

为查明内蒙古鄂温克旗那干楚勘查区的成矿特征及资源潜力,开展了已知矿床的地质特征、矿床成因类型研究以及物化探测量工作。结果表明,该区显生宙以来经历了多期次构造岩浆活动,内生金属矿床成矿地质条件优越。大民山组火山岩-碎屑岩地层、北东向断裂构造、燕山期中酸性脉岩对成矿有利;已知铜多金属矿体受北东向构造控制明显,多呈脉状产于大民山组地层中,具有中低温岩浆热液型多金属矿石的矿物组合和组构特征。综合信息分析表明,该区具有较好的银铜多金属找矿远景。根据1∶10000土壤地球化学测量和激电中梯测量异常特征,结合总结出的铜矿和铅锌矿的找矿标志,圈定化探异常8处,其中,4处异常最具找矿潜力。

To determine the metallogenic characteristics and ore-prospecting potential of Naganchu area in Ewenke Banner of Inner Mongolia,the geological features and genetic types have been studied,and geophysical and geochemical survey were carried on. The results indicate that since the Phanerozoic,this area experienced multi-stage tectonic-magmatism,which led to favorable ore-forming geological conditions for endogenous polymetallic mineralization,such as volcanic-clastic strata of Daminshan Formation,faults and fractures in NE trending,as well as mediate-acid intrusions during the Yanshanian. Polymetallic ore bodies discovered in this area mainly occur in the volcanic-clastic Damin Formation and obviously controlled by the NE trending faults. The ore has similar mineral assemblages,ore textures and ore structures as ones in mesoepithermal magmatic polymetallic ore. Integrated information indicates that the Naganchu area has favorable Ag- Cu polymetallic mineralization prospect.Based on soil geochemical survey in scale of 1∶ 100 00,induced polarization intermediate gradient survey and orefinding criterions concluded in this paper,there are 8 geochemical anomalies determined,in which 4 anomalies can be listed as the most favorable in exploration target areas.