Study On Sedimentary Environment Of Shanxi Formation In The Northwest Of Yangquan MiningArea

Paper by sequence stratigraphy, petrology, sedimentology and other disciplinestheory and method for guidance, through the analysis of typical drilling in the studyarea and indoor experimental study and combined with the comprehensive analysis ofmore than100Wells data, study on sedimentary facies and sequence stratigraphy,lithofacies palaeogeography, depositional environment and coal accumulatingcharacteristics in four aspects. In the study area of shanxi group identified,meandering river delta2types of sedimentary facies, five types of sedimentarysubfacies,10kinds of sedimentary microfacies, summarizes its characteristics.Through the sequence interface, into surface water, the water into theidentification, the shanxi group is divided into SQ1~SQ4four sequence, such as10systems tracts, established the sequence stratigraphic framework in the study area.Within the sequence stratigraphic framework shanxi group of sedimentary evolutioncharacteristics are discussed: SQ1period, in the study area, the types of sedimentarymicrofacies are mainly underwater distributary channel, underwater distributary bay,mouth bar; SQ2period, lowstand system tract mainly underwater distributary channel,water is conducive to the formation of8#coal seam in systems tracts of peat swamp;SQ3period, the ancient geography for delta plain, lowstand system tract mainlydistributary channel as a whole, with split between depressions deposits, water intothe system domain is given priority to with split between depressions; highstandsystem tract is given priority to with peat bog, conducive to the development of3#coal seam; SQ4period, palaeogeography of meandering river, give priority to withriver, point bar, development of natural levee.The development of coal seam is mainly controlled by sedimentary environmentsand tectonic, with the location of the channel and the continuous change ofhydrodynamic condition and water flow intensity and other factors.