珠江口盆地惠州凹陷恩平组浅水辫状河三角洲沉积  

SHALLOW BRAIDED DELTAIC SYSTEM IN ENPING FORMATION OF HUIZHOU DEPRESSION,PEARL RIVER MOUTH

作　　者：郭巧珍[1] 陈峰 杨香华[3] 舒誉 吴静 

机构地区：[1]新疆油田公司勘探开发研究院,克拉玛依834000 [2]中国石油西部钻探试油公司,克拉玛依834000 [3]中国地质大学资源学院,武汉430074 [4]中国海洋石油(中国)有限公司深圳分公司,深圳510240

出　　处：《海洋地质与第四纪地质》2013年第1期25-32,共8页Marine Geology & Quaternary Geology

基　　金：国家"十一五"科技发展规划国家重大专项(2008ZX05023-001-006-001)资助

摘　　要：珠江口盆地惠州凹陷恩平组广泛发育浅水湖泊,然而长期被认为是断陷湖盆的沉积充填模式。通过岩性组合、地球物理响应特征、古生物组合、地球化学指标、砂岩粒度特征等方面的综合分析,论证了在惠州凹陷恩平组沉积时期湖盆广阔平缓,湖泊淤浅,陆源供应充足,证实了在这种沉积背景下,发育浅水辫状河三角洲沉积体系。该体系具有三角洲平原、辫状河道极其发育,而河口坝等反旋回序列不发育等特征,该体系的提出揭示了研究区断拗转换期湖盆广、薄煤层发育、砂体分布广、沉降速率高、碎屑颗粒粗等沉积特色,与前人探讨的惠州凹陷恩平组的沉积面貌完全不同,为惠州凹陷古近系的勘探提供了新的理论和思路。Shallow lacustrine deposits are widely distributed in the Enping Formation of the Huizhou depression of the Pearl River Mouth Basin,and has long been considered as a kind of infilling of a faulted ba- sin. Through the study of lithology, geophysical responses, paleontology, geochemical proxies, and grain size distribution,this paper confirms that a special delta, shallow braided river delta, was developed in the En- ping Formation of the Huizhou depression in a broad shallow flat lake,with sufficient terrigenous deposits. And this system is characterized by a well-developed delta plain, an undeveloped coarsening-upwards sequence of a mouth bar,and a well-developed braided stream. Depositional features of shallow braided delta are widely observed, such as the lacustrine deposits formed in the fault-sag transition stage, wide-spread thin coal seam, high sedimentation rate, widely distributed sand body, and coarse deposits in the research area,totally different with the depositional-features of the infilling deposits in a faulted lake. The new model may help exploration in the Eogene of the Huizhou depression.

关 键 词：惠州凹陷 恩平组 浅水湖泊 浅水辫状河三角洲 珠江口盆地 

分 类 号：P736.22[天文地球—海洋地质]