--> New Geophysical Interpretations Combined With Remote Sensing and GIS Analysis for Structural Geological Studies in the Bornu Basin

AAPG Annual Convention and Exhibition

Datapages, Inc.Print this page

New Geophysical Interpretations Combined With Remote Sensing and GIS Analysis for Structural Geological Studies in the Bornu Basin

Abstract

Geoscientists routinely use common geophysical and geological mapping methods to study structural geological settings of sedimentary basins. However, traditional field methods are inadequate for mapping regional geomorphic features in remote areas that are characterised by flat topography and lack of adequate bedrock exposures. The applications of geological remote sensing and GIS to study the regional geospatial characteristics of surface geological features are therefore increasingly recognised. Available 2D seismic, ground gravity, satellite gravity, magnetic and well log datasets integrated with optical and radar remote sensing datasets are used in this research to study structural lineament features. The objective is to determine the synergistic relationship between the surface and subsurface structural styles identified from the multi-source datasets. The semi-arid intracontinental Bornu Basin in north eastern Nigeria is selected since previous field geological studies in the Bornu Basin remain constrained by flat topography and inadequate continuous bedrock outcrops. The methodology involves mapping of the palaeotectonic subsurface structural lineaments from the seismic, gravity and magnetic datasets as well as mapping surface lineaments from optical Landsat imageries. Surface lithological variations in the study area were delineated from the RGB colour composite optical images. The geomorphic characteristics detected from Synthetic Aperture Radar (SAR) and Advanced Synthetic Aperture Radar (ASAR) interferometry analysis indicated neotectonic (Quaternary) deformation in the basin. The subsurface structural analysis indicated patterns and alignments of the subsurface faults with the basement configuration. The local stratigraphic units in the study area were identified from correlated pattern analysis of the well logs and confirmed from the seismic sections. GIS analysis was carried out to establish the geospatial characteristics of the surface deformational features as geomorphic expressions of the basement lineaments mapped from seismic, gravity and magnetic data. The significance of the structural lineaments to the potential hydrocarbon systems and prospectivity of the basin are evaluated.