Abstract

Gravity survey in parts of Akataka and the environs in Abakaliki area of the Lower Benue trough was conducted over an area between longitudes 8°42′ E to 8°47′ E and latitudes 6°35′ N to 6°45 ′ N. Ninety eight gravity stations were occupied and the data collected were reduced relative to a base station. The geometry of the buried body was determined from the interpretation of residual anomaly data.  Spherical model was assumed for the anomalous body based on the local geology and the residual gravity anomaly. A density contrast of 0.32 gcm^-3 was calculated for the body. The residualized and interpreted gravity profiles yielded results that reveal low Bouguer gravity anomalies with magnitudes ranging from –2.5 to 3.8 mgals and with abrupt changes at intervals thereby suggesting a fault. The low-density anomalous body suspected to be salt deposit was buried at depths of between 868 and 2618 m. Its diameter ranging between 2,126 and 3,322 m, mass ranges from 1.18 to 4.52 × 10¹³ kg. The low Bouguer gravity anomaly over the area suggests a zone of basic to intermediate igneous intrusions, deep basement and crustal thinning. These calculated values are in agreement with other works carried out within Abakaliki areas in particular and the Lower Benue trough in general.

Key words: Gravity survey, profiles, Benue trough, intrusions, salt deposit, density.