【摘要】 在前人研究工作的基础上,结合了大量新的钻井、测井资料,以鄂尔多斯盆地镇原-泾川地区中侏罗统延安组为例,运用沉积学的方法详细阐述了研究区目的层位的岩相古地理演化特征,认为研究区延安组由下而上为河流沉积体系逐渐过渡为三角洲沉积体系。其中Y10段为河流相沉积,主要发育有心滩、边滩、河漫滩、岸后沼泽等沉积微相;Y9-Y6以三角洲沉积为主,主要发育的微相有分流河道、洪泛平原、平原沼泽等;Y4+5段发生了河流回春现象,河流相沉积再次发育。更多还原

【Abstract】 Based on studies of other people,new logging data and well drilling data,the article expatiated the Paleogeographic Evolution of target formation,taking ZhenYuan-JingChuan area in ordos basin as an example.From bottom to top of Yan’an formation,the sedimentary system from fluvial depositional system changed into delta depositional system.Channel bar,point bar,alluvial flat and backbank swamp etc are mainly fluvial microfacies which were developed in section Y10; distributary channel,flood plain and swamp etc are mainly delta microfacies which were found in section Y9-Y6;and fluvial deposition was developed again in section Y4+5.更多还原