Pattern analysis method of depositional environment from outcrop sections in coal measures

Coal-bearing series, also known as coal measures, are series of genetic connected sedimentary rocks with coal seams developed. Abundant mineral resources originated from coal measures. Researches on high-resolution paleoenvironment and paleoclimate reconstructions, stratigraphic cycles and their genetic dynamics are also based on coal measures analysis. Depositional environmental analysis is a significant method to investigate coal measures. In this paper, a depositional environmental analysis has been carried out on the outcrop sections in Carboniferous coal measures in Qilian Mountains. A pattern analysis method of depositional environment has been concluded based on previous researches and our field works. This paper focuses on the analysis procedure, procedure and analysis method of sedimentary environment in field work. A five-step method were summarized, including geological stratification and description, lithological summarization and environmental interpretation, sketch lithological section mapping, depositional modelling, and environmental evolutionary summarization. The contents and methods of the analysis pattern in every step have been provided. Geological stratification and description are the foundation of depositional environmental analysis. Lithological summarization and environmental interpretation are the core works in the analysis. Sketch lithological section mapping is the principle line in the pattern method. Depositional model and evolutional summary are the emphasis in the four-step method.