Deposition of coal-bearing measures and coal accumulation under marine transgression ‘events’ in North China epicontinental sea basin

摘要

In recent years, studies show that coal formed during marine transigression process is also important in coal accumulation basin. Still, the characteristics of coal formation is more clearly demonstrated by the coal formation in TST in the sequence strati graphic framework. Based on the study of the characteristics of coal formation in epicon tinental coal accumulation basin, the viewpoint that coal was formed under marine transgression was put forward by the authors and the mechenism thereof was also analyized.Marine transgression resulted in the forming of swamp and then the peat swamp. And the transgression later on put the peat formed in advance in deep water environment to form coal in the end. The important stratigraphic horrizons, such as coal seams, marine facies layers, formed with marine transgression are of the property of isochronism.