Gufeng Fm

Disconformable contact with limestone of the underlying Qixia Fm.

Conformable contact with the limestone of the overlying Wuxue Fm or the Yangqiao Fm.

The formation is lithologically stable and is distributed mainly in the Yangtze stratigraphic subregion. In the Nanjing, Caoxian, Anqing and Huaining areas the thickness of the formation ranges from 15 m to 20 m, with its base containing phosphorite nodules. In the Jingxian, Tongling and Guichi areas the thickness of the formation ranges from 30 m to 150 m, with its base representing manganese limestone. In the Shaoshui area of Quanzhou County, the Ertang area of Pingle County and Tongtianyan area of Liuzhou City, and Fenghua area of Laibin County of Guangxi the thickness of the formation ranges from 30 m to 150 m, intercalated with tuff. In the Enshi Region and the area to the north of Hefeng of Hubei Province, and in the area of Wangcang in the northeast of Sichuan Province on the northern margin of the Yangtze stratigraphic subregion the thickness of the Gufeng (Kufeng) Fm ranges from 100 m to 200 m, being also rich in carbonaceous and manganese substances, which are tend to be concentrated locally to form ore deposits. In Zhejiang Province the Gufeng (Kufeng) Fm used to be known as the Dingjiashan Fm established by Sheng Xinfu in 1951, and was renamed by Li Xingxue et al. in 1959 to be known as the Lijia Strata, which is commonly subdivisible into two members, with the lower member being known as the Dongwuli Member, representing siliceous rocks and black shale, with a thickness of over 40 m, and with the upper member representing a Stone Coal Layer, consisting of carbonaceous shale and stone coal, yielding ammonoids such as Daubichites, with a thickness of over 80 m.