1. Oil ＆ Gas Survey，China Geological Survey，Beijing 100029；2. School of Geoscience and Resources，China University of Geosciences，Beijing 100083；3. State Key Laboratory of Biogeology and Environmental Geology，Beijing 100083
Microbial carbonate is the product of microbes interact with the environment，and has important significance to the ancient environment and microbial community. There are thrombolites， laminates and stromatolites in Mesoproterozoic Gaoyuzhuang Formation from Pingquan area，Hebei Province. Thrombolites characterized by clotted fabrics is significantly different from the other microbialites who have the laminated structure. Thrombolite in Gaoyuzhuang Formation is divided into three types by the size and arrangement characteristic of their clotted fabrics. They are centimeter level dense mesoclot，millimeter level stratoid miniclot and micrometer layered microclot. Microscopic and ultra-microscopic observation showed that all the clotted fabrics are made up of core and outer layer. The main component of nucleus are the microorganism，like coccoidal and filamentous bacteria，or residual organic matter，surrounding by the radial or fan-shaped distribution of calcite shell，and mucus-to film-like extracellular polymeric substance （EPS） is visible between the calcite particles. Large quantities of residual microorganism and EPS found in clot showed that the formation of clot is closely related to the microorganisms. Different initial saturation of the environment may be the cause that formed different types of thrombolite.
Zhang Wenhao,Shi Xiaoying,Tang Dongjie et al. The characteristic and genetic interpretation of thrombolite in Mesoproterozoic Gaoyuzhuang Formation from Pingquan，Hebei Province[J]. Chinese Journal of Geology, 2016, 51(4): 1324-1343.