GENERATION ENVIRONMENT OF COAL MEASURE SOURCE ROCK IN THE EAST OF JIYANG AND LINQING, THE BOHAIWAN BASIN

Drilling,seismic,logging and testing data have indicated that,Carboniferous and Permian in the east of Jiyang and Linqing in the Bohaiwan Basin are mainly composed of a set of neritic carbonate platform facies limestone as well as barrier-lagoon,tidal flat,paludal and deltaic facies terrigenous clastic rock and coal bed.Vertically,in the Benxi Formation of the Upper Carboniferous,neritic carbonate platform facies carbonate rock and neritic continental shelf facies sand/mud stone are generated.In the Taiyuan Formation,a combination of barrier-lagoon,tidal flat,paludal facies carbonate rock,terrigenous clastic rock and coal bed is deposited.In the Shanxi Formation of Permian,deltaic facies and deltaic plane paludal facies sand/mud stone as well as coal are generated.In the Lower and Upper Shihezi Formation,offshore continental facies clastic rock is deposited,and in some places are fluvial paludal peat and coal generated.Sedimentary environment changes from neritic facies,marine/continental facies to continental facies,from bottom to top,south to north.The tidal flat,paludal and the deltaic plane paludal environments during the Taiyuan and Shanxi periods are most favorable for coal generation.