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.