Investigation of sedimentary microfacies and microbial rock in the Middle Cambrian Qingxiudong Formation in Panshi Town in Songtao County of Guizhou Province
The stratigraphy of the Qingxudong Formation in Songtao County in Guizhou Province of China reflects a complete microbial evolutionary sequence in which microbial rocks gradually flourished and then died-out after the extinction of Archaeocyatha in the Early Cambrian period.In this study,we examined the sedimentary microfacies of the Qingxudong Formation based on the measured Panshi section,layer-by-layer sampling,and identification and analysis of thinly ground sections.We identified 12 types of sedimentary microfacies:muddy striped microcrystalline limestone,Girvanella boundstone,epiphytic algal limestone,epiphytic pusillnm Korde algal limestone,Kenella algal limestone,Kenella algal containing limestone,Botomaella anabatica Voronova and Nicholsomia algal limestone,Renalcis chabakoviaformis Voronova algal limestone,algal arene limestone,arene limestone,microcrystal limestone,and calcareous mudstone.We also identified three types of upward-shallowing sedimentary sequences:mudstone-limestone-algal limestone,limestone-dolomitic limestone,and reef base-reef core-reef cover.We used these results to construct a model of the rimmed carbonate platform in the region where the Coralline algae were controlled by syn-sedimentary faults to reef at the margin of the basin.
万方数据
维普
