见天坝海绵礁发育于湖北省利川县见天坝(图1)上二叠统长兴组第二段。下伏地层长一段主要为盆地相黑灰色含泥质、有机质骨针和虫介屑粒泥岩与泥粒岩(即生物碎屑泥晶灰岩与泥晶生物碎屑灰岩),含燧石结核、团块以及条带,层内泥质纹层及不规则泥纹条带发育,底部含丰富的碳酸盐化的放射虫和海绵骨针,顶部厚10米的钙屑浊积岩是海绵礁的生长基底。钙屑浊积岩是由钙屑岩递交层的韵律层组成,钙屑主要成分 See Tianba sponge reef developed in the Lantian County, Hubei see Tianba (Figure 1) on the second Permian Changxing Formation. The underlying stratum is mainly composed of facies-facies dark gray muddy muddy, organic spicules and insect-borne mudstones and mudstones (ie, bioclastic mudstones and mud-clastic bioclastic limestones), flint-bearing nodules , Clumps and bands, muddy layers in the layers and irregular mud bands developed at the bottom with abundant carbonated radioactive insects and spongy bone needles. Calcareous turbidite with a top thickness of 10 meters was sponge Reef growth base. Calcareous turbidite is composed of rhythmic layers of calcareous rock layers, the main component of calcium flakes