摘要
早石炭世,桂林及其附近地区存在一组NE-NNE向的同沉积基底断裂。在断裂下降一侧,沉陷为海水水体较深的台沟,沉积有硅质岩、黑色页岩或炭质页岩组合类型;而在断裂相对上升一侧,则形成覆水较浅的碳酸盐台地,沉积有石灰岩和白云岩组合类型。在台地与台沟交接部位形成台地前缘斜坡相带。桂林南边村一带处于台地与台沟过渡地带的台地前缘斜坡相带,该区碳酸盐重力流沉积比较发育。按照碳酸盐重力流沉积物的沉积构造和岩石结构所反映的沉积物流动支撑机制,可以将本区的碳酸盐重力流划分为碳酸盐浊流沉积、碳酸盐颗粒流沉积和碳酸盐碎屑流沉积三种类型。
During Early Carboniferous there were a group of NE-NNE-striking cosedimentary basal fractures in Guilin and the adjoining areassuch as the Lingchuan-Yongfu fracture and the Quanzhou-Yangshuofracture, on the downfaulted side of which there was a platform basinor trough of deep and standing water, where an association of silicoli-tes-dark shale or carbonaceous shale was deposited; while on the uplif-ted side of which was formed a shallow water carbonate platform wherean association of limestone-dolomite was accumulated. Between the plat-form and the platform basin was formed a slope zone of the platformforemargin, where Nanbiancun of Guilin is just located.The carbonategravity flow sediments were well developed in the area.According to theflowing and supporting mechanism distinguished in the sedimentarytexture and structure of the carbonate gravity flow sediments, thecarbonate gravity flow may be broadly divided into three followingtypes: 1)The carbonate turbidites; 2) The carbonate grain flow depositsand 3) The carbonate slipping flow deposits.
关键词
碳酸盐
重力流
早碳世
桂林
carbonate
gravity flow
Early Carboniferous
Guilin
