浙江桐庐冷坞二叠纪生物礁的发育模式

礁体底部具脉状层理的潮坪相碎屑沉积，礁体内部藻叠层岩夹层的存在，及礁体上部为煤系地层覆盖等都表明冷坞生物礁是一个典型的二叠纪岸礁；海绵骨架岩的存在表明它是个骨架型岸礁。

Permian Reef Development Model in Lengwu Tonglu Zhejiang

The reef is located in Lengwu,Tongiu,Zhejiang.The tidal flat debris deposit with fiaser bedding underlying the reef, interbeds of algal stromatolite in the reef and coal measures strata overlying the reef,all of them indicate that it is a typical Permian fringing reef developed in shallow shore water.The presence of sponge framestone and biolainstone suggests it is a framed fringing reef rather than a deep-water knoll or mud -mound.The reef may be devided into 23 lithologio layers. Its development may have 9 cycles,each of them had several growth stages,began with the growth of sponges on rise of sea floor and ended with the death of the reefbuilders due to the waves or invasion of terrigenous clasts.Biolainstones,a type of reef rock with special environmental significance,are composed of skeletons of reefbuilders overturned by waves. The development of the reef could be comparable to the coral reef on the Ximao Island in South China Sea.