| Through the study of the existing data,uses sedimentology,sequence stratigraphy and geochemistry to guide,combined with wavelet analysis,spectrum analysis and lithofacies paleogeography analysis,the sedimentary evolution and coal accumulation law of Damoguaihe Formation in the study area are analyzed.In the study area,the sedimentary characteristics of each microfacies were identified and summarized.The Damoguaihe Formation is divided into four third-order sequences.In the third-order sequence framework,16 high-frequency sequences are further divided by wavelet analysis and frequency spectrum analysis.The high frequency sequence stratigraphic framework is established,and the sedimentary evolution of Damoguaihe Formation is traced,and the sedimentary model is established.The dominant coal accumulation cycle is established by using mathematical statistics method,in which the upper part of SQ2 and the lower part of SQ3,namely the high frequency sequence SQ2-3 to SQ3-2,are the best developed,with large thickness and many layers.Coal seams are mainly developed in peat swamp microfacies,and the controlling factors of coal accumulation are discussed.The development of coal seams is controlled by many factors,among which the spatial distribution of sedimentary facies controlled by structure restricts the spatial distribution of coal rich zone,and thick coal seams are mainly developed at the bottom of sequence relative Lake flooding surface and transgressive system tract. |
