Remote sensing and geosciences interpretation of lineaments for tectonic and hydrocarbon studies in the Bornu Basin, Nigeria

Geological conditions for hydrocarbon potential have been identified in the Bornu Basin in north Eastern Nigeria. The basin is part of the Chad Basin and other tectonically related contiguous basins within the West and Central Africa Rift System (WCARS) formed from the failed extensional rifting at an aulacogen junction during the separation of the South American and the African continents. The Bornu Basin covers about one tenth of the Chad Basin with limited geological mapping campaigns and unsuccessful exploration for oil and gas. Significant gaps still remain particularly in the vast northern areas characterised by flat topography, lack of continuous bedrock outcrops with structures concealed beneath sand cover. Remote sensing and GIS techniques offer potential for improving structural geological mapping in the basin but has not been used for these purposes. This research presents the use of combined remote sensing data including Landsat ETM+, ASTER, SRTM and Radar with other existing geosciences data including gravity, seismic, aeromagnetic and well log data to constrain the structure and tectonics of the basin through lineament analysis. The research involved mapping of lineaments, lithology, palaeodrainage and palaeo-shorelines in the basin. Two physiographically distinct study areas are selected in the basin to provide an appropriate comprehensive coverage of the basin attributes. The study sub-area 1 having mostly flat topography and lacking surface outcrops but comprising all the data sets available provides an enabling ground control site while the study sub-area 2 where outcrops are present provides an enabling site for validation of inferred field mapping and new observations of unmapped geology in the basin.