摘要
The microfacies from drilling cores near the Tazhong Slope Break I,Central High of the Tarim Block show variety of reef limestones.They are respectively recognized as coral framestones/bafflestones,spongia framestones/ bindstones,bryozoanal bindstones,calcareous algal bafflestones,calcified microbial bafflestones/bindstones.Based on the lithological character,nine ecological types are identified including coral reef,coral-algal reef,stromatoporoid reef,stromatoporoid-algal reef,coral-stromatoporoid-algal reef,bryozoanal reef mound,calcareous algal reef,carbonate mud mound and microbial reef.Occurrences of reef types are shown as vertically alternated of carbonate mud mound,coral-stromatoporoid-algal reef,bryozoanal reef mound and calcareous algal reef in ascending order.Their spatial distributions imply that the lower energy carbonate mud mounds are more favorably concentrated in interior settings of the platform;in contrast,coral-stromatoporoid-algal reefs are of the high energy indicators along the platform margin of the Slope Break I.Furthermore,differentiations of reef-building assemblages are also existed from well-limited blocks.Coral-stromatoporoid-algal reefs are of the major units of the high energy belts;they are surrounded by the coeval calcareous algal reef mounds as well as carbonate mud mounds of the low energy belts.