新疆东天山卡拉塔格地区中泥盆世玉带斑岩铜(金)矿发现的地质找矿意义

Discovery of the Middle Devonian Yudai Porphyric Cu(Au) Deposit in the Kalatage Area of Eastern Tianshan Mountain,Xinjiang and and its Geological Prospecting Significance

新疆东天山玉带斑岩铜(金)矿床产于卡拉塔格西段,其含矿围岩是一套火山岩-火山碎屑岩和大南湖组(D1d)含生物碎屑灰岩的碎屑沉积岩,矿体产于石英闪长玢岩体内及与围岩接触带,以石英-硫化物细网脉状矿化为主,矿石矿物以黄铁矿和黄铜矿为主,及少量磁铁矿、闪锌矿、方铅矿、辉钼矿等,矿区发育Cu-Au-Ag-Mo-Pb-Zn-As-Sb-Hg-Ba元素异常。矿床蚀变(>5km2)包括钠长石化、钾长石化、硅化、绿泥石化、绢云母化、水白云母化、高龄土化等蚀变类型,以含矿斑岩为中心向外可划分出钾(钠)化-绢云母化-硅化带、硅化-绢云母化(水云母+高岭土)-黄铁矿带和青磐岩化带(绿泥石-绿帘石化-碳酸盐化带)。围岩接触关系和同位素年代学研究显示玉带斑岩铜矿成矿时代为中泥盆世(391Ma),有别于土屋斑岩铜矿带,扩大了卡拉塔格地区及区域找矿空间。

The Yudai porphyric Cu（ Au） deposit lies in the west part of the Kalatage section of the East Tianshan Mountains. The ore- hosting rocks are Paleozoic volcanic,volcanic- clastics rocks and the lower Devonian Danan Formation（ D1d） clastic sedimentary interbeded with biogenic carbonates rocks. The mineralization occurred in the body of quartz diorite porphyrite and its contact zone. The ore- bodies mainly consist of quartz- sulfide veinlets. The main sulfide minerals are composed of pyrite and chalcopyrite with a small amount of pyrrhotite,sphalerite,galena and molybdenite. The metallogenic elements are Cu- Au- Ag- Mo- Pb- Zn- As- Sb- Hg- Ba. The range of alteration is more than 5km2 and the alteration types include albitization,potassic,sericitization,silication,epidotization,chloritization,carbonatization,hydromicaza tion,and kaolinization. The alteration zone can be divided into potassic ＋ albitization ＋ sericitization ＋ silication zone,silication ＋ sericitization（ hydromicazation ＋ kaolinization） zone,and propylitization（ epidotization ＋ chloritization ＋ carbonatization） zone from ore- bearing porphyry center outwards. The intrusive contact between the mineralized quartz diorite porphyrite and the lower Devonian Danan Formation（ D1d）,and the Zircon U- Pb dating indicate the Yudai porphyric Cu（ Au） deposit is located in middle Devonian（ 392Ma）,which is different from the Tuwu porphyric Cu deposit belt,and expands the prospecting potential space of the East Tianshan area.