吴川─四会断裂带的构造演化与金矿化的关系

加里东期，吴川─四会断裂带雏形开始形成，但金并未得到初步富集．海西期─印支早期，吴川─四会断裂带整体处于右行平移剪切状态，形成早期合金硅化岩脉．印支期，吴川─四会断裂带整体处于左行平移剪切状态，由此诱发粤西深层次及粤北中深层次逆冲推覆构造，并在主推覆滑动带中形成糜棱岩型金矿．燕山早期，已经抬升的吴川─四会断裂带在粤西、粤北一带继续发生继承性的韧─脆性逆冲推覆运动，在外来系统中形成破碎带蚀变岩型金矿．燕山中晚期，吴川─四会断裂带在NE向平移剪切、块断运动。NW及EW向断裂运动的联合作用下，形成晚期石英脉型金矿．

Tectonic Evolution of Wuchuan-Sihui Fault Zone and its Relationship with Gold Mineralization

During the Caledonian period,the embryonic form of the Wuchuan-Sihui fault zone began to form, which was companied by the planar greenschist facies metamorphism,but without the primary gold enrichment. From Variscan to early lndosinian period, the fault zone was wholly under dextral strike-slip shear state when the fault metamorphism and/or deformation of greenschist facies occurred. The early- stage gold bearing quartz veins and gold bearing silicified rock veins were formed in the process. In Indosinian period the fault zone was wholly under sinistral strike-slip shear state, which caused the formation of the deep-level thrust-nappe structures in western Guangdong and the middle - to deep- level thrust - nappe structures in northern Guangdong. The mylonite type of gold deposit was formed in this process in the main thrust fault zones. In the early Yanshanian period the elevated Wuchuan-Sihui fault zone underwent inherited ductile- brittle nappe thrusting, which formed the Jiaojia type of gold deposits in the allochthone. In the mid -late Yanshanian period the fault zone underwent NE sinistral strike-slip shearing, block faulting and NW and EW faulting, which formed the late stage quartz vein type of gold deposits.