广西丹池晚古生代沉积盆地的演化及控矿作用

右江海西期盆地主要归属于古特提斯构造域,具有大陆边缘裂谷盆地的性质,丹池盆地是该裂谷盆地靠近古陆边缘的次级裂陷盆地。丹池盆地的演化可分为陆内裂陷、被动陆缘裂陷、走滑裂陷、强烈拗陷和充填-关闭五个阶段。丹池锡-多金属矿带具有以断裂活动为主导,构造、地层、岩相、岩浆岩和矿床五位一体的成矿特点。讨论了海底火山喷气沉积-成岩交代、充填后期岩浆热液叠加改造的复合型矿床成因。

EVOLUTION OF THE DANCHI LATE PALEOZOIC BASIN IN GUANGXI AND ITS ORE CONTROL MECHANISM

The well-known Youjiang Late Paleozoic Basin in Guangxi, China, has clearly a feature of continentmarginal rifting, in which the Danchi Basin was developed as a secondary rift valley near the so calledJiangnan old land. Evolution of the Danchi Basin can be divided into five stages: intracontinental rifting,continent marginal rifting, strike-slipping, strong depressing and filling-closing. The ore control mechanism of the Danchi Basin tectonic and sedimentation evolution is as follows: (1) Synsedimentary faulting and rifting caused sea-floor volcanic emanation to afford a large quantityof metallogenetic material, which either deposited directly to form stratiform ores, or created a source-bed. (2) The compound effect of the NW extensional faults and the NE strike-slip faults in Middle and LateDevonian gave rise to secondary rises and depressions within the basin. The west and north west sides ofthe secondary depressions are the most favourable localities for ore deposition. (3) The favourable lithofacies are basin facies, reef facies, delta front facies and platform margin slopefacies. (4) Tectonic and magmatic activities to the end of the basin evolution not only provided with supplemen-tary metallogenetic material, but also facilitated activition, migration and enrichment of the metallogeneticelements.