粤东锡(钨、铜)多金属矿床的成矿物质来源和成矿作用

SOURCE MATERIAL AND METALLIZATION OF TIN (TUNGSTEN,COPPER) POLYMETALLIC DEPOSITS IN EASTERN GUANGDONG PROVINCE

粤东地区发育众多的锡（钨、铜）多金属矿床，主要沿３条北东向区域性断裂分布，组成西、中、东３个平行的成矿带。据矿床矿物组合，锡多金属矿床可确定为云英岩型、石英脉型、硅酸盐型和硫化物型４种矿床类型。钨、铜矿床较少发现。区内中生代岩浆活动强烈，火山岩和花岗岩广泛分布。研究认为，成岩与成矿的时差较小，成矿热液有岩浆分异的初始岩浆水及其所携带的Ｓｎ、Ｗ、Ｐｂ、Ｓ等参与。早期以岩浆水为主，晚期大气降水逐渐增加。西带和中、东带成矿的差异与硫同位素来源的差异和区域地层成矿金属元素背景含量差异有关，Ａｇ主要来自于区域沉积地层。

There are numerous tin (tungsten, copper) polymetallic deposits in eastern Guangdong Province and they are distributed along three NE trending fault belts: Haifeng Dapu (Feng shun) fault belt, Puning Chaozhou fault belt and Huilai Raoping fault belt. And they make up three metallogenic belts: Changpu Tashan metallogenic belt in the western area, Xiling Houpo'ao in the middle of the area, Zhongqiuyang Lianhuashan in the eastern area. Mesozoic granitic volcanic intrusive complexes as well as sandstones and shales of the Upper Triassic Xiaoping Group and the Lower Jurassic Jinji Group crop out widely over the region. According to main mineral assemblages, the tin polymetallic deposits are classified into four types: greisen type, quartz vein type, silicate type and sulfide type. The tungsten deposits and copper deposits are found fewer. The studies of isotope geochronolgy of some deposits and host magmatic rocks in combination with geological characteristics of these deposits show that the time intervals between the formation of host rock and the mineralization are small. The time space progressive changes of magmatism and metallization are identical. Constrains on H O S Pb multi element isotopic system, the metallogenic fluids are the mixed fluids of the evolutional meteoric water, the shifted meteoric water, the evolutional magmatic water and the pristine magmatic water. For a deposit, the magmatic water reduce and meteoric water increase from early stage to late stage and the pristine magmatic water is very important in the metallization. Based on regional geological background, the metallization differences between the western belt with the middle belt and the eastern belt are related to the differences of the sources of S isotope and the background contents of metallogenic elements in regional stratum. Ag mainly come from the T 3—J 1 sandstones and shales and Au mainly from Mesozoic granitic volcanic intrusive complexes. In addition, the ore forming process has been discussed. \ \