Study on sequence stratigraphy and coal accumulation function in Jixi Faulted Basin

In order to have the distribution features of the sequence stratigraphy framework in Early Cretaceous of Jixi Fault Basin,the related theory and method of the sequence stratigraphy was applied to the sequence stratigraphy analysis on the Early Cretaceous coal measures in Jixi Continental Fault Basin.The coal accumulation role of the Fault Basin was discussed.The study results showed that there were three sequence boundaries totally recognized in Early Cretaceous coal measures of Jixi Basin,two third grade sequences were divided and there were Chengzihe Formation and Muling Formation respectively.The seam accumulation mainly was subjected to the accommodation space variation rate and the peat accumulation rate.In the continental fault basin,the main factors to control the variation rate of the accommodation space and peat would be the tectonic activities and climate.Early Cretaceous period of Jixi faulted basin was in a stable development of a lake basin transited to a shrinking stage.In the stable development stage of the lake basin,the basement changing rate was gently,the terrigenous clastic supply was relatively less and the accommodation space increased rate and the peat accumulation rate were in a relevant balance.A delta plain was mainly developed and would be favorable to the seam accumulation.In the three grade sequences,a lake transgression system area would be best for the coal accumulation and the low level system area and the high level system area would be the second.