贵州天柱寨脚重晶石成矿地质特征及成矿模式

Geological characteristics and metallogenic model of barite mineralization in Zhaijiao,Tianzhu,Guizhou

通过天柱寨脚重晶石矿大精查,在寨脚-甲木冲一带老堡组顶部发现顺层产出的火山凝灰岩夹碳酸盐岩(灰岩)透镜,为重晶石海底喷流成因提供新的证据。通过钻孔岩心和露头沉积学特征观察,在重晶石矿床中见到丰富的滑塌构造、碎屑流构造和浊流构造,表明重晶石在喷流口初步堆积后,受到同沉积地质营力如地震、风暴作用形成震积岩,沿着斜坡向沉积盆地中心迁移并最终堆积成矿,形成大型、超大型的重晶石矿床。因此,重晶石矿床成因类型为海底喷流沉积矿床,建立斜坡水下重力流扇成矿模式。

Through the exploration of Zhaijiao barite ore in Tianzhu,a bedding-produced volcanic tuff intercalated with carbonate(limestone)lens was found on the top of the Laobao Formation in the Zhaijiao-Jiamuchong area,which is the origin of the barite submarine jet Provide new evidence.Observation of the sedimentary characteristics of borehole cores and outcrops shows that abundant slumping structures,clastic flow structures and turbidity current structures are seen in the barite deposits,indicating that the barites are subjected to syn-sedimentary geology after the initial accumulation of the vents.Seismites formed by the forces of earthquakes and storms migrated along the slope to the center of the sedimentary basin and eventually accumulated and formed large-scale and super-large barite deposits.Therefore,the genetic type of barite deposits is a submarine jet sedimentary deposit,and a slope underwater gravity flow fan mineralization model is established.