Abstract: Variable characteristics of the free air gravity anomaly and Bouguer gravity anomaly were analyzed by using the ship gravity data obtained from international cooperative survey between China and Nigeria. Through analyzing two gravity profiles that start from continental shelf, slope and extend to the deep sea basin, we can get the density structure of the crust. The results of research imply that the crustal thickness has been cascade thinning from continental shelf, slope to deep sea plain. The thinned range on the east side is greater than that on the west side, it decreases from 24 km to 10 km on the east side and 21 km to 14 km on the west side.

Key words: Nigeria, gravity anomaly, crust structure, Moho surface, gravity inversion