东昆仑纳赤台地区构造时空格架及成矿地质背景分析

Temporal-spatial framework of structure and geological background of mineralization of Nachitai area in East Kunlun Mountains

纳赤台地区位于东昆仑成矿带中段,为解决该区域重要成矿带基础地质矿产等方面的问题,开展了1∶5万基础地质矿产调查。结果显示:区内构造强应变带和糜棱岩化带交替频繁出现,脆—韧性剪切带中强片理化及糜棱岩化、S-C组构、旋转碎斑和不对称褶皱等构造现象常见,EW向、NWW向构造发育;新识别出的构造形迹和新发现的一些金铜铅锌等矿点及矿化线索,与区域上绝大多数矿床、矿点分布实例及EW向、NWW向线性构造带产出较一致,表明构造与成矿存在着直接或间接的关系。EW向、NWW向为主的构造与多金属矿床在时空和成因上有着密切的关系,昆仑河韧性剪切带形成时代为中—晚志留世(432～423 Ma),同区内新发现的二道沟白钨矿、铜金山钨锡矿的成矿时代较接近,认为该区域找矿潜力较大。

Nachitai area is located in the middle part of East Kunlun metallogenic belt. In order to solve basic geology and mineral resources problems in this important metallogenic belt, 1∶ 50 000 basic geological and mineral survey was conducted. The results show that strong strain zone and mylonitization zone are frequently alternate in the research area. The schistositized and mylonitized structures are common in the brittle-ductile shear zone, such as S-C fabrics, rotational porphyroclast and asymmetric folds. EW and NWW trending structures developed.The newly identified structural traces, combined with some newly discovered gold, copper, lead and zinc deposits and mineralization clues, are consistent with the majority of ore deposits, ore spots, and the occurrence of EW-NWW-toward linear tectonic belts in the region. This indicated a direct or indirect relationship between the mineralization and the structures. A closed relationship is shown between the EW and NWW structures and polymetallic deposits in time-space and genesis. Kunlun River ductile shear zone was formed in Late-Middle Silurian (432-423 Ma), which is similar to the newly discovered Erdaogou scheelite and Tongjinshan tungsten-tin ore in this reaserch area. This research shows that the potential of regional prospecting is great in this area.