新疆天山西段金矿找矿新进展

NEW PROGRESS IN SEARCHING GOLD-DEPOSITS IN THE WESTERN SECTION OF TIANSHAN,XINJIANG, CHINA

最近在新疆西天山西段靠近与哈萨克斯坦接界地区发现了一些金矿找矿新线索。值得特别关注的有两种矿化类型 ,有可能成为大型金矿 :即变质碳质碎屑岩型和破碎带蚀变岩型。本区首次发现了一套黑色碳质片岩和石墨片岩 ,其中发育有黄铁矿 -石英细脉 ,含金量达 9×1 0 - 6 ,与产于乌孜别克斯坦的穆龙套型金矿地质情况相似。还发现了铜 -金高含量矿化 ,即水磨沟铜金矿 ,该矿床产于一套蚀变的中 -基性火山碎屑岩中 ,矿体赋存于近东西向的断裂中 ,矿石由黄铜矿、斑铜矿、孔雀石、黄铁矿、石英、绿泥石组成 ,具角砾状构造 ,平均铜含量 6.1 % ,金含量 3 .8× 1 0 - 6 。分析了本区金矿成矿的地质特征 ,指出矿化带呈近东西向展布 ,集中于分割本区三个地体的两条大断裂附近的韧性剪切带中 ,绿片岩相的变质条件和花岗岩浆活动对金矿的富集有促进作用。这些新发现表明 ,新疆天山西段的地质条件与金矿化特征与其西部邻国地区相似 。

Several new clues of searching gold deposits have recently been discovered in the proximity of the boundary of Kazakhstan, western section of Tianshan, Xinjiang, China. Two kinds of gold deposits with high potential of becoming large scale mines are remarkable. One occurs in the carboniferous schist and the other occurs in the broken altered volcanic rocks. An interesting black rock formation, composed of carboniferous schist or/and of graphite schist, has been found, in which veins of pyrite quartz with Au content as high as 9 g/t develop. The gold mineralization is similar to that of Muruntar in Uzbekistan. Another new type of gold and copper mineralization, the Shuimogou gold deposit has also been found. It developed in a formation composed of altered mafic to intermediate clastic volcanic rocks. The ore body is located in the fault striking from west to east, with an association of chalcopyrite, bornite, pyrite, malachite , quartz and chlorite. The average content of gold and copper of ores is 3.8 g/t and 6.1%, respectively . The geological studies show that the gold mineralization developed in the ductile zones is distributed from west to east, near to the two great faults separating the three terrains in the area, and that the hydrothermal fluid derived from the green schist facies metamorphism and from the granite magma activity would promote the gold mineralization. The new discovery also demonstrates that the geological conditions and gold mineralization in this area are similar to those of the western neighbouring countries, and that the Central Asia Metallogenic Zone would extend to east into Xinjiang, China.