Discovery of a probable meteorite impact crater off the W coast of South Africa

Abstract:

We describe a probable submarine meteorite impact crater, discovered offshore the west coast of South Africa, using industry 3D seismic data. The feature is roughly circular, with a diameter of about 10 km; it has some depth extent and disrupts underlying strata. Two major possibilities exist for its origin: that it is an igneous diatreme or that it is a meteorite impact crater. We assess both possibilities through a detailed description of its morphology and seismic characteristics. Although a line of known alkaline volcanic pipes does project towards the coast, comparison of this feature with similar structures worldwide leads us to suggest that the crater is more likely to have formed through the impact of a meteorite. Using simple scaling relationships, we estimate the likely size of the impactor and attempt to arrive at an age limit by extrapolating the ages of mapped horizons from a borehole, located at a distance of approximately 5.5 km.