论文部分内容阅读
综合运用岩心、测井、钻井等地质资料,对车西洼陷古近系沙河街组沙三下亚段—沙四上亚段沉积相类型及其分布特征进行了系统研究。结果表明研究区沙三下亚段—沙四上亚段共发育了近岸水下扇、湖底扇、扇三角洲、三角洲、碳酸盐滩坝、滨浅湖和半深湖—深湖7种沉积相类型,从沉积相平面分布特征来看,车西洼陷北部陡坡带受埕南大断层持续活动影响,自下而上发育多期次近岸水下扇,多期扇体纵向上相互叠置,横向上沿着埕南断层下降盘呈“裙带状”分布;洼陷带发育北部物源的湖底扇;南部缓坡带主要发育物源来自于义和庄凸起和无棣凸起的三角洲;湖泊边缘、湖湾及水下隆起周围靠近缓坡侧的滨浅湖地区发育碳酸盐滩坝。
The sedimentary facies types and distribution characteristics of the Shahejie Formation in the Shahejie Formation of the Paleogene in the Chexi Sag are studied synthetically using the geological data of core, well logging and drilling. The results show that there are 7 species of nearshore subaqueous fan, sublacustrine fan, fan delta, delta, carbonate dam, coastal shallow lake and semi-deep lake-deep lake From the sedimentary facies distribution, the northern steep slope belt in the north of Chexi Sag is affected by the continuous activity of the Taonan fault, and the multi-period nearshore subaqueous fan develops from bottom to top. In the horizontal and vertical directions, the downdip of the Taonan fault is distributed as a “zonal band”; the subduction zone develops the lake-bottom fan of the northern source; the main developmental source of the southern ramp zone comes from the Yihezhuang uplift and Wudi convex Deltaic lakes; and the carbonate shoal dam has been developed at the edge of the lake, the lake bay and the shallow coastal lake near the gentle slope near the submarine uplift.