西非毛塞几比盆地漂移期盆地边界精细厘定
The Definition of Basin Boundaries in the Drift Phase of M.S.G.B. Basin in West Africa

毛塞几比盆地位于西非北部，是典型的被动大陆边缘盆地，也是目前非洲油气勘探重点盆地。该盆地历经50余年勘探，但仍缺乏对该盆地的深入了解，盆地边界未能精确厘定。本文研究将目标定位于毛塞几比盆地漂移期，在明确盆地周缘构造演化过程、基底及盖层展布的前提下，通过盆地结构和地层反射关系、盆地周边构造、盆地古地理分析以及基底性质四个方面研究对盆地边界进行划分。将盆地的边界划分为沉积控制边界、构造控制边界和岩石圈性质控制边界三种类型。认为盆地东部边界为沉积类型边界，地层上超于东北部的埃格拉格雷贝特山地盾以及东部毛里塔尼亚褶皱带，盆地边界受不同时期古地理格架的影响；盆地南北两侧边界为构造边界，受盖？布朗斯断裂带，南部发育受几内亚断裂带控制，以两条转换断层形成的构造高点为盆地边界；西侧边界由岩石圈性质所决定，以大西洋洋壳与洋陆过渡壳分界为盆地边界。
M.S.G.B. basin is a typical passive continental margin basin and an important area for oil and gas exploration which is located in the north of West Africa. The basin has been explored for more than 50 years, but there is still a lack of in-depth understanding of the basin. There are still dis-putes on the analysis of basin boundary. This study will target the drift period of the M.S.G.B. Basin, based on the basin structure and stratigraphic reflection relationship, the surrounding structure of the basin, the paleogeographic analysis of the basin, basal properties as well as the structural evolution process of the periphery of the basin, the distribution of basement and caprock. Four aspects of basement properties are considered to divide the boundary of the basin. The boundary of the basin was divided into three types: sedimentary control boundary, tectonic control boundary and lithospheric property control boundary. The eastern boundary of the basin is a sedimentary type boundary. The stratigraphic is over lap on the northeast of the EgraGrebert mountain shield and the Mauritanian fold belt in the east. The sedimentary type boundary of the basin is affected by the paleogeographic framework in different periods. The boundary on both sides of the basin is the tectonic boundary which was controlled by the Cap？Browns fault zone in the north and the Guinea fault zone in the south, with the structural high point formed by two transition faults as the basin boundary; the western boundary is determined by the nature of the lithosphere, and the boundary between the Atlantic oceanic crust and the oceanic continental transitional crust is the boundary of the basin.