为查明鄂尔多斯盆地西部耿湾-史家湾地区延长组长6时期物源状况,揭示该地区沉积体系的分布格局,文章通过常规矿物成分、重矿物、岩屑、地球化学特征和地震剖面等多种研究方法,对耿湾地区的物源及源区母岩性质等进行了系统分析。结果表明,该地区主要受到3个方向物源控制,即东北、北西和西南部,其中东北物源是控制区内沉积的最主要物源。古物源与沉积体系空间配置关系良好,并从根本上决定了长6时期的沉积体系分布格局以及砂体展布方向。
In order to determine the distribution pattern of the depositional system of the Upper Triassic Yanchang Formation in the Gengwan area of Ordos basin, the authors did a systematic research on the characteristics of the mother rocks in the provenance by analysing the rocks and minerals, heavy minerals, rock fragment character, geochemical character and seismic profile, etc.. The results indicate that the Gengwan area is mainly controlled by three great sediment source regions, that is, the northeast, northwest and southwest provenances. The Oengwan area is located in the transition belt of the three depositional systems. The paleo-provenance determines the depositional system pattern of the Chang-6 (Member 6 of Yanchang Formation) oil-bearing reservoir and will be useful to a reasonable deployment of oil-gas exploration.