A Bouguer gravity map of nigeria
Abstract
A compilation Bouguer gravity map using four published networks covers about 40% of the area of Nigeria. The Niger delta, which is close to isostatic equilibrium, overlies oceanic crust and anomalies in its Cretaceous frame are attributed to volcanic rocks and thick sediment sequences. To the northeast the Benue trough is marked by a central positive anomaly with negative anomalies on either flank. These may mark the sites of miogeoclinal accumulations on the sides of an embryo Benue Ocean which opened in the Cretaceous and closed by the beginning of the Tertiary. The Benue trend persists under the Quaternary sediments of the Chad basin. The regional negative anomaly of the Jos plateau has a wavelength of 100 km and a northwesterly strike. It is associated with Neogene to Recent uplift and volcanism and with Recent faults. Exposed and unexposed Jurassic granites which have a density contrast with the basement of 0.06 g/cm 3 show up clearly within this regional anomaly.
- Publication:
-
Tectonophysics
- Pub Date:
- January 1973
- DOI:
- 10.1016/0040-1951(73)90134-0
- Bibcode:
- 1973Tectp..16..103A