珠江口盆地白云凹陷恩平组物源转换及沉积充填演化
Provenance Transformation and Sedimentary Evolution of Enping Formation,Baiyun Sag, Pearl River Mouth Basin

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.
In order to clarify the sediment supply and sedimentary filling evolution, seismic attributes and seismic facies, the sediment supply and infilling evolution are studied by analyzing the changes in sedimentary environment, morphology, the shape and chronology of the detrital zircons, and the characteristics of sand-bodies,based on the main measuring method of the paleogeomorphology, paleontology, LA-ICPMS zircon U-Pb dating. The results indicate that the sediment supply and sedimentary filling have greatly changed during different sequences of the Enping Formation. During the SQ1 and SQ2 of the Enping Formation, the sedimentary environment was characterized by lacustrine rift basins with relatively small sedimentary-range. The sediments around the paleo-uplift were composed of Mesozoic igneous rocks and interpreted to have sourced via relatively short-distance transportation. The southern steep slope zone mainly developed a series of medium-small scale proximal fan deltas. The northern slope zone mainly formed a series of braided deltas with typical channel-filling and beach-bar sand-bodies, and the sediments were mainly derived from the Panyu lower uplift and Dongsha uplift. During the SQ3 of the Enping Formation, the sedimentary environment was characterized by semi-closed bay with relatively large sedimentary range.The sediments mainly derived from the South China Folded Belt which were composed of Precambrian-Paleozoic metamorphic rocks. The activity of the syn-depositional faults in the southern steep slope zone gradually weakened and mainly formed a series of small scale proximal fan deltas with the sediments provided by the southern uplift. The northern slope zone was interpreted to havesourced via relatively long distance transportation and deposited along the northwest-southeast trending, forming three stages large scale prograding braided deltas