A number of prospect companies have undertaken geophysical and drilling operations in the areas surrounding the Delta, and the Geological Survey has mapped the region around Lake Ngami and conducted gravity and seismic investigations in the swamps. As a result, bedrock lithologies have been inferred with a fair degree of reliability and major structural elements have been determined. Satellite imagery (LANDSAT 1) studies have also contributed to an appreciation of the tectonic history of the region.