东天山康古尔塔格-沙泉子走滑断裂控矿机制研究

The eastern Tian Shan is an important polymetallic metallogenic belt in China and its metallogenic mechanism of mineralization is a research hotspot at home and abroad. The existing researches mainly focus on petrography, ore deposits, isotope chronology and deep geophysical exploration. However, ore-controlling mechanism in multi-spatial scale caused by macroscopic tectonics and regional fault，especially strike-slip fault，is ignored in the past. Thus, in this research project, we shall focus on the strike-slip fault zones and their secondary structural units in Kanggurtag-Shaquanzi metallogenic belt related to the mineralization of Cu, Ni, Au in the eastern Tian Shan to work out spatio-temporal correlation between geometric and kinematic characteristics of strike-slip faults and metallogenic factors based on the extraction and interpretation of fault structure, alteration rock and intrusive rock from multi-source remote sensing data. After analyzing spatial relation of mineralized alteration and the geometric, kinematic as well as geomorphologic characteristics of strike-slip fault system in the typical ore deposits/ mineralized spots of the Kanggurtag-Shaquanzi metallogenic belt in detail, spatio-temporal aggregation relation between ore deposits and strike-slip faults will be established and the three-dimensional evolution model of tectonic ore-controlling will be reconstructed in order to reveal metallogenic advantages and ore-controlling mechanism of strike-slip fault in the eastern Tian Shan. The results from this project will be expected to provide new scientific data and technical support for further exploration and target optimization of large ore deposits throughout Tian Shan.

东天山是我国重要的金属矿产成矿带，其机理研究是国内外研究的热点。现有研究大多聚焦于岩相学、矿床学与同位素年代学及深部物探的成矿研究，很少涉及从多尺度空间上开展宏观板块构造格局与区域断裂（尤其是走滑断裂）几何学特征的控矿机制研究。因此，本项目基于多源遥感数据对断裂构造、蚀变岩及侵入岩岩性等信息的提取与分析，对走滑断裂几何学、运动学特征与成矿要素的时空关联性问题，以东天山康古尔塔格-沙泉子Cu-Ni-Au成矿带的走滑断裂及次级构造为研究对象，通过解析典型矿集区的主要矿床（矿化点）的蚀变、断裂构造几何学、运动学及地貌学特征之间的空间相关性，厘定走滑断裂与各类型矿床成矿的时空关系，构建三维构造控矿演化过程，阐明走滑断裂构造的最佳成矿条件，揭示东天山走滑断裂的控矿机制，为东天山地区大型金属矿产靶区优选及进一步勘查提供新的科学数据与技术支撑。

本项目于2019年1月1日立项，至2021年12月31日结题，共实施3年。研究计划、研究方案、研究内容及研究目标完全按照《资助项目计划书》的要求执行，未做任何更改。本项目先后考察了新疆东天山康古尔塔格-沙泉子沿线黄山、康古尔、雅满苏、土屋4个多金属矿区的露头、区域断裂、矿石及矿脉，采集了成矿岩体、围岩、剪切带岩样共计138件。本研究主要内容包括：（1）基于样品光谱特征，建立了ASTER遥感影像VNIR-TIR波段全谱域的成矿岩性信息识别方法，提取出研究区矿化与侵入围岩岩性的空间分布特征；（2）识别与解译了研究区高精度DEM数据的区域走滑断裂遥感影像特征，厘定了康古尔Ni-Cu成矿带与区域走滑断裂构造及次级断裂构造的空间关系；（3）综合分析了多源遥感成矿要素信息时空分布特征，重建了东天山黄山等典型金属矿床的康古尔走滑断裂构造控矿三维演化过程。本研究主要成果包括：（1）实现了ASTER遥感影像VNIR-SWIR波段b2/b1、b6/b7与b4/b8，TIR波段MI、CI与SI指数综合的研究区岩性信息识别方法，理清了Ni-Cu富集区片理化闪长/辉长岩包围苏长岩的空间分布特征；（2）测定了康古尔右行走滑断裂几何学特征，指明了矿化点明显受与康古尔断裂垂直或倾斜的次级断裂控制，成矿空间主要分布于EW和NEE走向的右旋走滑断裂交汇部位；（3）发现了二叠纪碰撞后右旋剪切伸展构造强烈控制基性/超基性岩浆的地壳浅层侵入、二叠纪-石炭纪小型杂岩体侵入，揭示了东天山黄山-康古尔走滑断裂弯曲压缩变形部位控制基性-超基性岩的侵入就位及次级断裂协同作用的控矿机制。本项目研究成果阐明了东天山走滑断裂构造的控矿机制，为东天山及中亚造山带金属矿产靶区优选及进一步勘查提供新的科学数据与技术支撑。