摘要:为进一步整体研究鄂尔多斯盆地侏罗纪沉积体系及古地理演化特征，笔者通过野外剖面实测、钻井资料分析并结合前人研究成果对盆地发育地层进行详细研究。研究结果表明鄂尔多斯盆地侏罗系发育有冲积扇、河流、三角洲、湖泊沉积体系。在古地理演化过程中，早侏罗世富县期沉积以填平补齐为特征，仅在河道及两侧发育河流相沉积，济源地区发育浅湖相沉积。中侏罗世延安期延10亚期开始河谷宽度扩大，高地进一步缩小，主要以河流相为主，济源湖面积有所增大，延9亚期是三角洲体系发育早期，也是最大湖侵期，盆地西部及北部仍为曲流河沉积，向南逐渐过渡到三角洲沉积，在志丹—延安—济源一带发育浅湖沉积；延8亚期局部构造抬升，三角洲平原进一步扩大，河流向湖泊进积；延7—延6亚期，盆地稳定填充，延4+5亚期湖泊面积缩小，延3、延2及延1亚期构造抬升，河流回春，盆地进入萎缩阶段。中侏罗世直罗期—安定期在盆地周缘发育冲积平原，内部主体为河流—三角洲—湖泊沉积。晚侏罗世芬芳河期仅在盆地西缘发育冲积扇沉积。
关键词: 鄂尔多斯盆地/
侏罗纪/
沉积相
Abstract:In order to further study the Jurassic sedimentary facies and paleogeographic evolution of Ordos Basin, the author made a detailed study on the developed strata of Ordos Basin through field measurement, drilling data analysis and previous research results. The results show that there are alluvial fan, river, delta and lacustrine sedimentary systems in Ordos Basin during Jurassic. In the process of paleogeographic evolution, the sediment of Early Jurassic Fuxian Period were characterized by filling and leveling, only fluvial facies deposits are developed in the river channel and both sides, and shallow lacustrine facies develops are developed in Jiyuan area. During the Middle Jurassic Yanan Period, the width of the valley began to broaden and the highlands further narrowed, mainly in fluvial facies, and the area of Jiyuan Lake increased. The early development of the delta system was also the largest lake transgression stage in Yan-9. The western and northern parts of the basin was still meandering river deposition, which gradually transition to delta deposition to the south, and shallow lake deposition was developed in Zhidan-Yanan-Jiyuan area. During the Yan-7~Yan-6 subperiod, the basin was filled steadily, the lake area decreased in the Yan-4+5 subperiod, and during the Yan-3, Yan-2 and Yan-1 subperiods, the river revived, and the basin entered the shrinking stage. During Zhiluo-Anding Period of Middle Jurassic, alluvial plain was developed around the basin, and the main part of the basin was fluvial delta lacustrine deposit. In the Fenfanghe Period of Late Jurassic, only alluvial fan deposits developed in the western margin of the basin.
Key words:Ordos Basin/
Jurassic/
Sedimentary Facies
PDF全文下载地址:
http://www.dzkx.org/data/article/export-pdf?id=6055fd8e-ec42-4978-8313-5e1a5d754e1a
