尼日尔三角洲盆地构造演化对沉积的控制作用

Tectonic Evolution of the Niger Delta Basin and Its Control on Sedimentation

尼日尔三角洲是一个拥有丰富石油和天然气资源的盆地,目前已探明的石油和天然气储量高居世界排名第十二位。盆地发育有较多的巨型结构和一系列与重力有关的构造类型,根据其构造特征的差异将其划分为逆冲型、泥拱型以及逆冲—泥拱混合型。通过古构造恢复结合沉积展布分析,得出结论:中新世托尔托纳晚期沉积开始受构造活动控制,托尔托纳阶上部及以上地层具有明显的同沉积特征,泥收缩构造相关的冲断裂上升盘厚度明显小于下降盘厚度,褶皱两翼的地层厚度明显厚于中间背斜顶部的地层厚度。

The Niger delta basin is an one rich in oil and gas resources with the proven reserves of oil and gas ranking twelve in the world.Many giant structures and a series of gravity-related structures were developed in the basin・These structures may be divided into thrust type,mud arch type and thrust-mud arch hybrid type.Paleostructure restoration combined with sedimentation distribution indicates that the Late Miocene Tortonian deposits began to be controlled by tectonic activity and the upper part of the Tortonian is obviously synsedimentary and thickness of hanging wall of thrust fault associated with mud contraction structure is obviously smaller than the thickness of footwall,and the thickness of strata on the climbs of the fold is obviously thicker than that on the top of the middle anticline.