Bioherm developed in the middle of the Wujiaping Formation is less than 100 m thick and belongs to marginal reef of intra-basin platform on shelf.The main features of the bioherm are: 1.It is a low range upwarp which is made of white massive rocks within visible lamination. 2.It contains abundant reef-building organisms such as calcisponges

blue-green algae

Tubiphytes

green algae and red algae. The content is usually 25-30%

locally above 75%. 3.It is composed almost completely of pure carbonate rocks without chertsand terrigenous debris. 4.It has a complete facies assemblage of slump microbreccia in reef-front

algae-sponge reef limestone in reef core and gymnocodium micrite in back-reef. The primary reef-building organisms are calcisponges

tabulozoans

Anthraco-porella

blue-green algae and Tubiphytes. The first group organisms are supporting and baffling ones

and the last two are binding and encasing ones.