琼东南盆地中中新世重力流海底扇沉积特征及控制因素

发布时间：2018-10-11 09:43

【摘要】：以往研究认为琼东南盆地陆架坡折形成于中新世末期,而在中新世早中期盆地北部为古斜坡地形。通过对琼东南盆地中新统坡折带、区域海平面、三角洲与重力流海底扇沉积的关系分析,结合钻井、地震等资料确定了琼东南盆地中中新世海底扇沉积特征及控制因素。结果表明,在中新世早中期盆地北部发育沉积、断裂和挠曲3种类型坡折,海底扇的沉积分布主要是受到沉积坡折控制,尤其是10.5Ma区域海平面下降时期,陵水凹陷、乐东凹陷发育早、晚2期大型富砂海底扇,早期海底扇沉积在陵水凹陷,浊积水道迁移快,数量多但下切作用不强;晚期海底扇沉积在乐东凹陷,浊积水道稳定分布,数量少,下切明显,朵叶体平面呈扇形分布,海底扇水道和朵叶体是有利的沉积单元。
[Abstract]:It is considered that the continental shelf slope break of Qiongdongnan basin was formed at the end of Miocene and the northern part of the basin was paleo-slope in early and middle Miocene. Based on the analysis of the relationship between Miocene slope break zone, regional sea level, delta and gravity flow submarine fan deposition in Qiongdongnan Basin, combined with drilling and seismic data, the sedimentary characteristics and controlling factors of Miocene submarine fan in Qiongdongnan Basin are determined. The results show that three types of slope break are developed in the northern part of the basin in the early and middle Miocene. The sedimentary distribution of the submarine fan is mainly controlled by the sedimentary slope break, especially in the period of sea level drop in the 10.5Ma region, the Lingshui sag. Ledong sag developed early, late 2 large sand rich seabed fan, the early submarine fan deposited in Lingshui sag, the turbidite water channel migrated quickly, the quantity was large, but the undercut action was not strong, the late submarine fan deposit was in the Ledong sag, the turbidite water channel was distributed stably, and the quantity was less. The plane of the flower body is fan-shaped, and the submarine fan channel and the flower body are favorable sedimentary units.
【作者单位】：中海石油(中国)有限公司湛江分公司;
【基金】：国家科技重大专项“莺琼盆地高温高压天然气成藏主控因素及勘探方向”课题(编号:2011ZX05023-004)资助
【分类号】：P618.13

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