Abstract:

Xiaodonghai coral reef situated in the south part of Hainan Island isa fringe reef.δC¹⁴-dating shows that it developed about 8000 years ago.The texture constituents in reef rocks include reef-building organic frame-work which consists mainly corals,reef-philic organic skeleton fragments,boulders of organic framework,and bioskeleton mud and silt.They areregularily distributed in the certain part of reef flat.Diagenesis of reef rocks has its specific features which is dominated bythe process of organism in which adhesion and encrust acted a principlerole.These diagenetic process reflected different sedimentary environmen tsand their changes. In this paper the authors intend to discribe and discuss the adhesion andencrust of coral,coralline algae and foraminifera,and the fill of bioske-leton mud and silt,etc.These process usually were occurred together,andthey are controlled by sedimention-diagenesis environments.The similar diagenetic process are quite common in ancient reef or reefrocks.They are good keys to recognize ancient sedimentary facies and envi-ronments.