【摘要】 通过重矿物、岩屑及碎屑成分的特征研究,认为鄂尔多斯盆地延长组主要受到3大物源控制,并且可进一步划分出6个次级物源;岩性、古生物对比和物源、古地理研究证明,在延长组中期,不存在来自正东方向的"富县三角洲";通过长7高阻泥岩、有效烃源岩分布特征及沉积相、地震相研究,认为盆地底形具有"南陡北缓、西陡东缓"的特点,这种特点造成了盆地东北部主要属于缓坡型湖泊三角洲体系,而在南部、西南部则属于陡坡型扇三角洲及三角洲前缘末端的浊积扇沉积。这些认识必将有助于今后盆地的油气勘探部署。更多还原

【Abstract】 Based on the research of heavy minerals,debris and clastic composition,the paper indicates that there are mainly three sediment source regions and six sub-source areas in Ordos Basin.The authors consider that the Fuxian delta from the east sources does not exit in the Yanchang mid-period by studying the provenance and paleogeography and comparing lithology and paleontological.Finally,the paper also discusses the bottom shape of the lake basin of Yanchang period in Ordos based on the research of the distribution feature of mudstone of Member 7 of Yanchang Formation,effective hydrocarbon source rocks, seismic profile and sedimentary facies.The results show that the basin is wider in the north,steeper in the south,steeper in the west and wider in the east of Ordos Basin,and at the same time,the northeast delta belongs to a gentle-slope lake delta system,but the south and southwest delta mainly belongs to a steep-slope fan-delta and there exists turbidite fan sediment on the end of the delta front.These recognitions must be helpful to the oil and gas exploration of Ordos Basin in the future.更多还原