湘黔桂浅变质岩区含金建造及其与金矿的关系

The Au-Bearing Sedimentary Sequences and Their Impact on The Gold Deposits in Light Metamorphic Rock in the Boundary of Hunan,Guizhou and Guangxi Regions

湘黔桂相邻区中、新元古界浅变质岩系的含金建造多为斜坡-盆地相、深水-较深水、远源-中源的浊流沉积,常富含凝灰质、碳质及硫化物,属于活动大陆边缘地壳强烈拉伸环境的产物,形成于扬子古大陆裂陷和再度裂陷时期。中、新元古代火山活动为其提供了丰富的成矿物质,多数成为原生含金建造,个别成为衍生含金建造。这些含金建造在形成之后,先后遭受了区域埋深变质作用、区域动力变质作用,以及脆韧性、脆性剪切作用,最终形成了变质细碎屑岩型金矿。

In the Meso-Neoproterozoic light metamorphic rock series in the boundary of Hunan, Guizhou and Guangxi regions, most of the Au-bearing sedimentary sequences are turbidity current sediments, formed in basin or slope facies, deep-water or deeper-water depositions. Their materials are far-resource or mid-resource, and are often enrich-tuffaceous, carbonaceous and sulfide rocks. These sedimentary sequences are formed in active margins where crust had been strongly stretched druing the rifting of the Yangtze block. There are abundant sources of ore-forming materials because of volcanic activity. Most of them are primary Au-bearing sedimentary sequences, and others are derivitization. The Au-bearing sedimentary sequences suffered from the deep-buried metamorphism, low-temperature dynamic metamorphism and brittle-ductile shearing, leading to the occurrence of extensive elements fractionation and Au-enrichment and the formation of gold deposits of metamorphosed fine-clastic rock type finally.