山东黄县盆地古近系李家崖组含煤岩系沉积相特征及演化

山东黄县盆地是中国东部一个重要的煤和油页岩共生盆地,古近系李家崖组是盆地主要的含煤岩系发育层段。根据层序地层学理论,建立了古近系层序地层格架;依据钻测井、岩心资料划分了李家崖组的沉积相类型,编制了分体系域的沉积相图。主要结论如下:(1)李家崖组发育湖泊、辫状河三角洲以及扇三角洲3种沉积相类型。(2)层序Ⅰ低水位体系域以辫状河三角洲相为主,湖扩展体系域以扇三角洲相和湖泊相为主,高水位体系域以扇三角洲相为主;层序Ⅱ低水位体系域以辫状河三角洲相为主,湖扩展体系域以扇三角洲相和湖泊相为主,高水位体系域以湖泊相为主。(3)层序Ⅰ发育时期: 低水位期盆地初始形成—湖扩展期盆地扩张—高水位期盆地萎缩;层序Ⅱ发育时期: 低水位期盆地再次缓慢扩张—湖扩展期盆地加速扩张—高水位期盆地萎缩消亡。

Sedimentary facies characteristis and evolution of coal-bearing rock series of the Paleogene Lijiaya Formation in Huangxian Basin,Shandong Province

Huangxian Basin in Shandong Province is an important basin rich in coal and oil shale in eastern China. The Paleogene Lijiaya Formation is the main strata of coal-bearing rock series in the basin. According to the theory of sequence stratigraphy,the sequence stratigraphic framework of the Paleogene was established. Based on drilling,logging and core data,the sedimentary facies of the Lijiaya Formation were classified,and sedimentary facies maps of different system tracts of the Lijiaya Formation were compiled. Main conclusions are as follows: (1)Sedimentary facies of lake,braided fluvial delta and fan delta were developed in the Lijiaya Formation. (2)In sequence Ⅰ,the lowstand system tract mainly developed braided fluvial delta facies,the lake extension system tract mainly developed fan delta facies and lacustrine facies,and the highstand system tract mainly developed fan delta facies. In sequence Ⅱ,the lowstand system tract mainly developed braided fluvial delta facies,the lake extension system tract mainly developed fan delta facies and lacustrine facies,the hightstand system tract mainly developed lacustrine facies. (3)During the depositional stage of the sequence Ⅰ,the basin experienced the formation period in the lowstand system tract,the expansion period in the lake extension system tract and the shrink period in the highstand system tract. During the depositional stage of the sequence Ⅱ,the basin experienced slow expansion period in the lowstand system tract,the expansion period in the lake extension system tract and the shrink period in the hightstand system tract.