The coral fringing reef of Weizhou Island is-based on the volcanic rocks.Except the lower temperature of sea water in winter and vigorous growth ofbrown algae in spring

the environmental factors are suitable for coral growth. This fringing reef is a young one

which has been formed since about 3100years B.P.. Most of the reef-building corals are massive colony which form theframework of the reef. and the branching corals only have a secondary position. There are two provenances of sediments: 1. The coral growing zone and thereef flat is the provenance of fringing reef carbonates

and 2. The sea cliff ofthe volcanic rocks became the provenance of terrigenous clastics. Thase debris aretransported and mixed by the sea currents and tidal energy with lateral and ver-tical migrations in the coastal zone and then accumulated in an asymmetric ringform in plane. The composition of the sediments is mainly consisted of shell debris

coraldebris and terrigenous debris. They are characterized by higher shell debris andlower algal debris

This is the main difference deffering from those of the IndoPacific

the Carribean and other coral reefs in the South China Sea.