The Research About The Distribution Of Fractures And Depressions In Liberian Basin Based On Gravity Data

We required the distribution of fractures, depressions and the sediment thickness in Liberia Basin by processing the gravity anomaly from satellite altimetry anomaly and analyzing the processing result.The research shows that there are three 1st-order NEE-trending fractures which are the southern boundary of Liberia Basin and control the deposition of the basin, two 2st-order NW-trending fractures which are the northeast boundary of Liberia Basin and control the deposition of the basin and three 3st-order NE-trending fractures which are located in the basin and control the distribution of the depressions. The formation time of the NW-trending fractures are older than that of the NEE- or NE-trending fractures.The constructive pattern of depression-uplift-depression has been displayed from north-east direction to south-west along the seacoast of the researched area. The northeastern depression zones are located in the land, the middle uplift area is located in continental shelf of Liberian. And the southwestern depression is located in continental slope. The southwestern depression has been divided into four secondary depressions with the maximal sediment thickness of 8000 m and the depression area of about 14183 km2. Additionally, there is a triangle-shaped depression in southwestern of Liberia with the maximal sediment thickness of 6000 m and the depression area of about 6826 km2. The Harper Basin, with the area of about 17278.65 km2 and the maximal sediment thickness of 7800 m, is located in the southeast of the researched area.