珠江口盆地白云凹陷恩平组物源转换及沉积充填演化

发布时间：2019-01-14 17:05

【摘要】：为了阐明白云凹陷古近系恩平组的物源供给方式及沉积充填演化规律,以古地貌-古生物分析、LA-ICPMS锆石U-Pb定年、地震属性分析及典型地震相识别为主要技术手段,对白云凹陷恩平组不同沉积时期的沉积环境、古地貌特征、锆石形态及年代组成、砂体发育特征等进行分析,认为恩平组沉积时期其物源供给方式及沉积充填特征发生了明显的变化.恩平组SQ1~SQ2时期陆相断陷湖盆特征明显,沉积时期沉积范围较小,以盆内短程物源(中生代火成岩基底母岩)供给为主:南部陡坡带主要发育近源快速堆积而成的扇三角洲;北部缓坡带发育充填结构典型的辫状河三角洲及上倾尖灭明显的滩坝砂体.恩平组SQ3时期主要为半封闭的海湾沉积环境,沉积范围较大,以盆外远程物源(华南褶皱带前寒武纪-古生代变质岩基底母岩)供给为主:南部陡坡带断裂活动减弱,发育规模较小的扇三角洲;北部缓坡带发育沿北西-南东方向展布的三期前积反射并不断向盆地中心进积的典型大型辫状河三角洲.
[Abstract]:In order to elucidate the source supply mode and sedimentary filling evolution law of the Enping formation of Paleogene in Baiyun depression, paleogeomorphology paleontology analysis, LA-ICPMS zircon U-Pb dating, seismic attribute analysis and typical earthquake recognition are the main technical means. The sedimentary environment, paleogeomorphology, zircon morphology and age composition, sand body development characteristics of the Enping formation in Baiyun depression are analyzed. It is considered that the material supply mode and the sedimentary filling characteristics of the Enping formation changed obviously during the sedimentary period. The characteristics of continental faulted lacustrine basin in the SQ1~SQ2 period of the Enping formation are obvious, and the sedimentary range is relatively small during the sedimentary period. The short-range provenance in the basin (the Mesozoic igneous basement parent rock) is mainly supplied. The fan delta formed by the rapid accumulation of the near source is mainly developed in the southern steep slope zone. The braided river delta with typical filling structure and the beach bar sand body with obvious updip tip are developed in the north gentle slope zone. The SQ3 period of the Enping formation is mainly a semi-enclosed bay sedimentary environment, with a large sedimentary range, mainly supplied by remote outbasin provenance (Precambrian-Paleozoic metamorphic basement parent rock) in the South China fold belt, and the fault activity of the southern steep slope belt is weakened. Developing a small fan delta; A typical large braided river delta is developed in the northern gentle slope zone, which is distributed in the north-west to the southeast direction of the basin and is reflected in three stages of progradation and continuously precession to the center of the basin.
【作者单位】：中国地质大学构造与油气资源教育部重点实验室;中国地质大学资源学院;中海油研究总院;
【基金】：国家科技重大油气专项(Nos.2011ZX05023-001-015,2011ZX05023-001-001)
【分类号】：P618.13

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