Sequence stratigraphy and coal-forming laws in Pingzhuang basin of Inner Mongolia

The sequence stratigraphy of coal measures in the Pingzhuang basin has been studied by drilling core data and field geologic survey.Applied theoretics and methods of sedimentology,sequence stratigraphy and coal geology,judged by the surface of palaeotectonics and large scale erosion surface,Xingyuan Formation and Yuanbaoshan Formation which are coal measures of Pingzhuang basin,were divided into one supersequence and two sequences;and then the sequence was subdivided into LST,LTST,LCST and NLST;the sequence of stratigraphic characteristics were expounded;at last,the relationship of sequence stratigraphy and coal-forming law were summed up.It is indicated that in the LST and LTST there is basically no coal-forming action;in the LCST locally has thin coal seams without industrial development value;the NLST has favorable coal-forming conditions,formed thick coal seams.