江玛—赛登地区铜多金属矿点地质特征及找矿前景

Geological Characteristics and Prospecting Potential of Jiangma-Saideng Copper Polymetalli Ore Spots

藏北阿里江玛—赛登地区铜多金属矿点位于班公湖—怒江成矿带西段,通过开展矿产调查工作在该地区发现了赛登铜矿点、江玛铜金矿点、江玛南铜银矿点。为明确区内下一步找矿方向和工作重点,首先对区域成矿背景进行了系统分析;然后分别从矿体形态及产出、矿物组合、矿石结构构造、控矿因素、围岩蚀变等方面总结了矿床地质特征;最后分析了成矿机理,初步建立了矿床模型,总结了区内地层、岩体、构造、蚀变等找矿标志,并对区内找矿前景进行了探讨。研究结果表明:1去申拉组地层对区内铜多金属矿化的控制作用十分明显,其中蚀变安山岩与成矿关系密切;2赛登铜矿化体主要产出于NW—SE向顺层产出的蚀变破碎带内,江玛南铜银矿化体受火山机构控制明显;3江玛铜金矿化、金矿化主要产出于蚀变安山岩和蚀变石英闪长玢岩中;4矿区剥蚀程度较小,矿床保存尚好,寻找斑岩型-浅成低温热液型矿床前景良好,下一步工作重点是被地表安山岩覆盖的深部含矿隐爆角砾岩筒及含矿玢岩体。

The copper polymetallic ore spot that has been newly discovered in Jiangma-Saideng district is located in the west of the Bangong Co-Nujiang metallogenic belt. The Saideng copper ore spot,Jiangma copper-gold ore spot and Jiangma south copper-silver ore spot are found in Jiama-Saideng area by conducting the mineral resources survey work. In order to discuss the prospecting potential,firstly,the regional metallogenic background of Jiangma-Saideng area is analyzed systematically;then,the geological characteristics of the deposits of Jiangma-Saideng copper polymetallic ore spots are summarized from the aspects of morphology characteristics and occurrence characteristics of the ore-bodies,mineral assemblage characteristics,ore texture and ore structure,ore-controlling factors,wall rock alteration; finally,the metallogenic mechanism of Jiangma-Saideng copper polymetallic ore spots is discussed,the deposit model is established preliminary,the prospecting indicators are summarized from the aspects of stratum,rock mass,structure and alteration,based on the above analysis results,the prospecting potential of Jiangma-Saideng area is studied in depth. The analysis results show that： ①the copper polymetallic mineralization of JiangmaSaideng area is controlled obviously by the Qushengla formation stratum,the altered andesite is closely related to mineralization; ②Saideng copper mineralization bodies are occurred along the stratum altered fracture zones which orientation is NW-SE,Jiangma south copper-silver minalization bodies are controlled by volcanic mechanism; ③ Jiangma copper-gold mineralization bodies are occurred in the altered andesite and quartz diorite porphyrite; ④the denudation degree Jiangma-Saideng copper polymetallic ore spots is low,and the deposits are carefully preserved,the prospecting potential of porphyry-epithermal deposits,the focus of the next prospecting work is the deep ore-bearing cryptoexplosive breccia and ore-bearing porphyrite that are covered by the surface andesite.