为典型的滨海陆源碎屑沉积，岩性以灰白、肉红或紫红色中、厚层石英砂岩为主，夹粉砂岩和砂质页岩，产植物化石。底部以浅灰、灰白色石英砂岩与下伏小溪峪组的黄绿、黄灰色含较多的管状体砂岩、粉砂岩分界，岩石厚509.19m。The formation is a typical set of coastal terrigenous detrital sedimentary rock strata. The strata is mainly composed of grayish white, pinkish red and purple red medium- and thick-bedded quartz sandstone, with interlayers of siltstone and sandy shale, containing phytolite (plant fossil). The bottom boundary is between the light grey and grayish white quarts sandstone and the yellowish green and yellowish grey sandstone and siltstone containing tubular structures of the underlying Xiaoxiyu Formation. The thickness of the formation is 509.19m.