为深灰、灰色中厚-厚层瘤状泥质灰岩与灰岩互层。含笔石:Orthograptus sp.,Glyptograptus sp.,Climacograptus sp.,Tetragraptus cf. bigisby;三叶虫为Taihangshania sp.,Szechuanella szechuanensis,Asaphopsis sp.