Paleobathymetric influence on the development of the late Ediacaran Yangtze platform (Hubei, Hunan, and Guizhou provinces, China)

Abstract

A compiled facies map based on 48 sections positioned in three Chinese Provinces (Hunan, Guizhou and Hubei) and field data emphasize the changes in depositional environments on the shelf of the Ediacaran Yangtze Platform. The facies interpretation suggests three depositional environments: (1) a deep-water basin with a slope facies on its margins (Maoping and Wuhe sections, Hubei Province); (2) Intertidal or shoals environments subjected to wave energy (Yangjiaping and Zhongling sections, Hunan Province; Wengan section, Guizhou Province); (3) a shallow-water subtidal shelf environment, subjected to currents (Xikou section, Guizhou Province). During the Doushantuo Formation time period (∼ 635 Ma–551 Ma, [Condon, D., Zhu, M.-Y., Bowring, S., Yang, A., Jin, Y.-G., 2005. U–Pb ages from the Neoproterozoic Doushantuo Formation, China, Science. Science, 308, 95–98.]), the shelf showed an irregular bathymetry, interpreted as inherited from the rifting history of the Yangtze Platform following the break-up of Rodinia (approx. 700 Ma). The tilted blocks influenced the platform development, and the facies distribution. Locally, more than the Doushantuo Formation time period (∼ 84 Ma) has been necessary to compensate the variations of bathymetry inherited of the tilted blocks geometry.