胜利油区石炭二叠系含煤地层层序地层学初探

Sequence stratigraphy of the CarboniferousPermiancoalbearing strata in the Shenglipetroleum province, Shanxi

胜利油区石炭二叠系含煤地层包括中石炭统本溪组、上石炭统太原组和下二叠统山西组。可识别出潮坪沉积、障壁岛湖沉积和三角洲沉积三种沉积类型。根据区域地质及古生物资料，确定了三个等时面，划分出２个层序１４个准层序，每个层序包括低位体系域、海侵体系域及高位体系域，而以高位体系域最发育。纵观整个含煤地层的沉积演化过程，本溪组沉积期以滨浅海相为主；太原组沉积期为海陆交替相；山西组沉积期以三角洲相为主，总体表现为海退层序。

The Carboniferous-Permian coal-bearing strata in the Shengli petroleum province, Shanxi consist of the Middle Carboniferous Benxi Formation,Upper Carboniferous Taiyuan Formation and Lower Permian Shanxi Formation.Three depositional types may be recognized,including tidal-flat,barrier island-lagoon and deltaic deposits.In the light of regional geological and palaeontological data,three isochronous surfaces are deter- mined,and two sequences and fourteen parasequences are delimited in this paper.More precisely,each sequence is made up of lowstand,transgressive and highstand systems tracts,the latter one of which is best developed.The examination of sedimentary evolu- tion of these coal-bearing strata have revealed that the Berxi Formation was accumulated in the littoral-shallow marine facies,Taiyuan Formation in the alternating terrestrial-marine facies,and Shanxi Formation in the delta facies.