Stromatolites of the Ediacaran Dengying Formation in Hefeng, western Hubei Province and its ecological environment discussion

This paper is the result of geological survey engineering.

Objective The Ediacaran Dengying Formation in the Central−Hubei Platform of the Yangtze region hosts abundant stromatolites, yet there is a lack of systematic reports on them. This study aims to address this gap by identifying stromatolite types in the Dengying Formation at the Baiguoping section in the southwestern part of the platform. Through this, we analyze the sedimentary environment, aiming to elucidate the influence of the ancient environment on stromatolite distribution. The insights gained serve as a valuable reference for future research on Ediacaran stromatolites in the Central−Hubei Platform.

Methods  Utilizing section surveys and microscopic observations, this study identifies stratiform and columnar stromatolites in the dolostones of the Ediacaran Dengying Formation at the Baiguoping section. Stratiform stromatolites include flat−laminated, Stratifera, and wavy−laminated forms, columnar stromatolite see the Baicalia form genus.

Results  In the southwestern Central−Hubei Platform, these stromatolites are associated with various environments: Periodic exposure settings for the flat−laminated and Stratifera forms, lagoon environments for the wavy−laminated form and intertidal to upper subtidal zones for the columnar stromatolites. Published data reveals that during the deposition period of the Ediacaran Dengying Formation, stratiform stromatolites were abundant on the Yangtze Platform, meanwhile columnar and other stromatolite forms were rare, indicating limited morphological diversity.

Conclusions  The scarcity of stromatolite variations can be attributed to widespread shallow water niches and locally deeper water niches resulting from long−term stable tidal flat environments in the Yangtze Platform.