Implications of Tectonic Anomalies From Potential Field Data in Some Parts of Southeast Nigeria.

Abstract

Tectonic structures controlling mineralization in some parts of Southeast Nigeria were evaluated using airborne potential field data. High and low frequency filters and depth determination tools were adopted to evaluate short and long wavelength anomalies, resolve the spatial spreading of igneous intrusions, depths to geologic sources and basin topography. The high frequency results exhibited high concentration of short wavelength anomalies in the Obudu Plateau and Ikom-Mamfe Rift. The underlying main tectonics of the area elucidated by the low frequency results caused the widespread occurrences of short wavelength geologic structures that are revealed by the high frequency maps. The study area is characterized by comparatively thin (~13.0 to <3000 m) sedimentation. The observed thin thickness is as a result of the massive Precambrian basement outcrops in some locations in the Obudu Plateau and the proliferation of igneous intrusions within this part of the Lower Benue Trough. The 2-D models showed the undulating nature of the underlying basin topography, the location of intrusions, domal structures and related normal faults. The locations and neighbourhood of intrusions and/or short wavelength structures are viable sites for lead-zinc-barite, brine and metallogenic minerals.