Stromatoporolds-coral patch reefof Lateordovlcaln Sanjushan Formation In Dashanjlaoof Yushan

Jlangxl Province

developed on an isolated carbonateplsteform In Sanshan region.It is a complex and multlcycle superimposed reefcomposed vertlcallyby two patch reefs.Themain reef-building organisms are Tabulato

stromatoporolds andalge.Basedon the paleoecology of reef-building organisms

they could be divided into four communities.It is consideredthat the rock types of the reef complex are dominantly baffflestone

bind-bafflestone

bafflebindstone and algal binded framestone.Reef fades may be divided into five subfacles such asreef base

reef core

interreef deposit

reef talus and reef cap.The reef core underwent clearlythree evolution cycles.The evolution of the reef was controlled by structures and the fillingof argillaceous debris.