A carbonate microscopic image dataset of Sinian Dengying period in northwestern margin of Sichuan Basin

The Sinian Dengying Formation on the northwestern margin of the upper Yangtze is the first set of large-scale carbonate rocks deposited in the upper Yangtze region after the end of the Nanhua ice age. It not only records the response of Sinian to global climate warming, but also records the evolution of marine microorganisms and the growth of carbonate rocks before the outbreak of Early Cambrian skeletal animals. At the same time, the dolostone formed by these microorganisms is becoming the target of oil and gas exploration of deep ancient carbonate rocks in Sichuan Basin. Therefore, the microscopic images of 154 thin sections collected from the Qingping and zhenbaluchi sections in Mianzhu, northwest margin of the Yangtze platform, reveal that the composition and structural characteristics of the rocks vary with time. On the section, the sequence of siliceous rocks, micritic dolostones, algal laminar dolostones and granular dolostones is generally shown, which reflects that under the background of continental margin sea in the northwest margin of Yangtze platform, a slow sea is formed In the process of sea level rise, the growth and development process of carbonate platform margin affected by secondary sea level fluctuation. The data set can be applied to the study of rock microfacies of Sinian Dengying Formation in the northwest margin of Yangtze platform. It can also be used in the interdisciplinary research such as image intelligent recognition. It can also provide a basis for the social production activities such as oil and gas reservoir description, genetic mechanism analysis, teaching and popular science Basic information service.