内蒙古大兴安岭中北段铜铅锌金银多金属矿床成矿规律与找矿方向被引量：144

The Metallogenetical Characteristics and Prospecting Direction of the Copper-Lead-Zinc Polymetal Deposits in the Northern-Central Daxing'anling Mountain,Inner Monglia

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摘要本文根据内蒙古大兴安岭中北段地质构造演化、成矿特征、中俄蒙邻近地区矿产分布和近年来的地质和找矿工作进展,划分了地质构造单元和成矿区带,总结了该地区主要矿床类型和成矿时代分布规律,提出了多金属矿的找矿方向。本文将大兴安岭中北段划分为额尔古纳地块、鄂伦春晚华力西褶皱带和东乌旗早华力西褶皱带3个Ⅲ级构造单元,细分为满洲里-新右旗中生代火山-深成岩隆起区等14个Ⅳ级构造单元。工作区主要矿床类型有矽卡岩型、斑岩型、热液型,其次为海相沉积型、岩浆熔离型、砂矿型和云英岩型,其中斑岩型和热液型矿床是主要矿床类型,热液型矿床可以细分为6个子类型。矿床的分布总体上具有北东呈带、北西成行特点,根据矿床的分布和区域构造特征可以分为德尔布干和东乌旗-兴安两个北东向Ⅲ级成矿带,13个Ⅳ级成矿区。从成矿时代上看,矿床的形成经历了从早古生代至晚中生代的很长时间,而以晚中生代为主。但不同类型矿床的成矿时代分布有很大差异。单一的斑岩型铜(钼金)矿从早古生代延续至燕山期,而其他类型矿床均形成于燕山期。提示在大兴安岭今后的找矿工作中对于矽卡岩型和热液型矿床主要集中于燕山期构造岩浆活动区,而斑岩型矿床找矿则应同时注意古生代和中生代等构造岩浆活动区。 Based on geological evolution and metallogenetical characteristics in central-northern Daxing＇anling, and the distribution characteristics of ore deposits at the adjacent areas in Mongolia and Russia, the geological units and metallogenetic zones are divided, the main types of the ore deposits and metallogenetical ages are summed up, and the direction of ore prospecting in the belt is proposed, The Daxingeanling metallogenetical belt is divided into three third-order geological units, i.e. Ergun block, Orogen Hercynian fold belt and Dongwuqi early-Hercynian fold belt, which can be subdivided into 14 fourth-order geological units. The main types of ore deposits are dominated by skarn, porphyry, hydrothermal, VMS, magmatic differentiation, placer and greisen, with porphyry and hydrothermal deposits being the main types. The hydrothermal ore deposits can be subdivided into 6 secondary types. The ore deposits are characterized by northeastern-striking distribution zone and a northwestern array. Two third-order metallogenetic zones （Deerbugan and Dongwuqi-Xing＇an metallogenic belts） and 13 fourth- order metallogenetic enrichment belts can be divided based on ore distribution and the characters of main ore-controlling structures. The formation of deposits in the belt lasted a long period from early Paleozoic to late Mesozoic era, with the latter being the main period. The mineralization of various types of ore deposit is quite different. An individual porphyry copper （Mo and Cu） deposit might last from early Paleozoic to late Mesozoic, whereas others formed mainly during the Yanshanian. It is suggested that the future prospecting for skarn-type and hydrothermal type deposits in the Daxing＇anling must concentrate on the Yanshanian tectonomagmatic active areas, whereas the prospecting for porphyry deposits on the Paleozoic and Mesozoic tectonomagmatic active zones.