右江沉积盆地演化与微细浸染型金矿床成矿作用关系探讨

RELATIONSHIP BETWEEN EVOLUTION OF THE YOUJIANG SEDIMENTARY BASIN AND METALLOGENESIS OF MICRO-DISSEMINATED GOLD DEPOSITS

右江沉积盆地在大地构造位置上被称为右江印支褶皱带,其沉积—构造演化可划分为3个阶段:大陆边缘裂谷、弧后裂谷和坳陷盆地。桂西北地区是右江盆地的主体部分,该区典型微细浸染型金矿床(金牙、高龙)的含矿硅质岩特征、矿床的地质特征、地球化学特征、矿石组构学特征一致表明矿床在沉积成岩期已形成,矿床属同生沉积成因。矿床的形成与右江沉积盆地演化密切相关。裂谷环境、盆地的岩相古地理、同沉积断裂等因素对矿床的形成起重要的控制作用。

The Youjiang sedimentary basin was referred as Youjiang Indosinian folding belt. Tectono-sedimentary evolution of the basin may be divided into three stages like continental margin rift, back-arc rift, and depression basin. The main part of the Youjiang basin is located in the northwestern Guangxi province. In the area, the characteristics of ore-hosting siliceous rocks, geology, geochemistry and fabric in typical deposits like Jinya, Gaolong suggest that these deposits are syngenetic in origin. Gold mineralization in the studied area is closely related to the evolution of the Youjiang basin. Rift setting, litho-facies and palaeogeography of the basin and syn-sedimentary faults have played important roles in formation of the deposits.