Akwasi Acheampong Aning, Piotr Tucholka, Sylvester K. Danuor
The 10.5 km diameter Bosumtwi meteorite impact crater in Ghana was formed about 1.07 million years ago. It is the source crater of the Ivory Coast tektites strewn field. The crater is occupied by a lake of diameter 8.5 km. Electrical resistivity tomography (ERT) survey using the multi-electrode gradient array was carried out along sixteen radial profiles around the lake to determine the sediment/bedrock contact, impact related structures and the impact direction of the meteorite. The data were corrected for topography and inverted using the L1–norm. The subsurface images highlighted areas that are characterized by faults, fractures, lake sediments and impact related breccias such as allochthonous and parautochthonous breccias and dikes. The sediment/bedrock contact, which marks the crater geometry, was successfully mapped and it shows symmetry in the NE–SW direction and dips between 160 in the NE to 360 in the SW. The faults were mostly delineated in the west and they dip averagely 600 to the east and 800 to the west. The dips of the faults were statistically treated and were found to have a preferred direction. The results of the crater geometry and the orientation of the faults indicate that the meteorite came from the NE.
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