HOLOCENE RAISED BEACH SEDIMENTS AND THEIR DIAGENESIS, WEIZHOU ISLAND.GUANGXI

At many places along the coast of Weizhou Island, the coral fringing reefs has developed. Correspondently, the beach sediments consisted of bioclasts developed at the beach. The Holocene beach sediments were rised to the land, and the highest place is about 5m,higher than the present sea level.They are more or less cemented and become an im portant building material for the local residents, In the quarries various deposital structrues can be observed, They are even-stratification with sea- ward dip about 3-10(the major occurrence)，fine-coarse sand-gravel bioclasts in- tercalated beds large scale tabular cross-beddings small cross-bedding， lens of coar- se grain, etc, They represent the products of swash zone, surf zone, beach cusp and storm.