【摘要】 鲁西、苏北地区中寒武统张夏组上部主要是藻灰岩与鲕粒灰岩互层沉积。根据藻类的宏观结构可划分为藻礁、藻叠层石、藻丘及藻斑块.显微镜下观察藻类主要由Epiphyton组成。根据沉积相分析,研究区自东南而西北张夏组上部可划分为藻礁相、鲕粒滩相及藻坪相。藻灰岩的沉积与环境条件是密切相关的,其主要影响因素有海平面变化、沉积速率、碎屑物源供应及水动力条件等。更多还原

【Abstract】 The upper part of the Zhangxia Formation (Middle Cambrian) in the North Jiangsu- West Shandong region consist dominantly of the intercalations of algal limestones and oolitic limestones.Macroscopically the algae may be divided into reef,stromatolite mound and biscuit,and microscopically are mostly composed of Epiphyton.Three distinct facies have been distinguished in the upper part of the formation on the basis of sedimentary fa- cies analysis:the algal reef facies,oolitic shoal facies and algal-flat facies.The environmen- tal factors such as sea-level changes,depositional rates,sediment supply and hydrodynami- ca| conditions are all responsible for the formation of the algal limestones in the study area.更多还原