Abstract:

The Neoproterozoic was a critical time in the history of the earth, because it was the time of the most extreme climate change that yielded numerous glacial deposits over the world. The Neoproterozoic strata in the Three Gorges area, as a representative of the regional succession of western Hubei, has being rigorously studied. However, the Neoproterozoic sequence of the Three Gorges area was incomplete, whereas the corresponding stratigraphic succession was better developed in the neighboring West Shennongjia area. Overlying the Mesoproterozoic Shennongjia Group, the Nanhuan (Crygenian) System at the Gaoqiaohe section in the West Shennongjia area, presented in this paper, is composed of the Liantuo, Gucheng, Datangpo, and Nantuo Formations in ascending order and overlaid by the Sinian (Ediacaran) Doushantuo Formation. The regional correlation with the typical Neoproterozoic stratigraphical sections from the Three Gorges and Changyang areas indicates that the Nanhuan System at the Gaoqiaohe Section is one of the most complete and continuous lithostratigraphic sequences in the western Hubei, and it can be used as a perfect reference for the regional stratigraphical division and correlation and for the study of the extreme climate change through the critical time.

Key words: Nanhuan System, stratigraphical sequence, paleoclimate change, Gaoqiaohe section, western Hubei