The lower part formed in a littoral - epeiric environment , is a series of elastic rocks , partly contains carbonate rock and metamorphic basic volcanic rocks and the upper part formed in a bathypelagic environment is a series of sediments with chert , partly contains metamorphic basic volcanic rocks 其下部为一套滨浅相碎屑岩，局部夹碳酸盐岩、变质基性火山岩；上部为一套深水沉积岩系夹硅质岩，局部夹变质基性火山岩。
