- © 2006 Geological Society of South Africa
This is the story of changing paradigms, regarding the understanding of our planet and its position in space – of geocentric and heliocentric views, but mainly in the earth sciences, over the last several centuries. This is also the story of the revolutionaries –Copernicus, Lyell, Hutton, Van Hoff, Wegener and Du Toit, Dietz and Hess, and finally Shoemaker. It is the story that begins with the Babylonian geocentric but flat worldview, moves on to the heliocentric perspective of the Greek philosopher Aristarch, via the geocentric dogma of the pre-Copernican Middle Ages and Copernicus’ revision, to the Cataclysm Theory, and then the beginning of Modern Geology in the form of gradualism and actualism, to continental drift that spawned plate tectonics, and finally to Planetary Science. This new view of the universe includes what I would like to call the New Catastrophism, incorporating the catastrophic forces of the important natural catastrophic processes affecting this planet. The nature of impact cratering as a fundamental universal process and the tools for the recognition of impact structures will be examined, and the role of this process since beginning of accretion and planet formation, and leading to the question whether past impact catastrophes have, at times, spurned major mass extinctions in Earth’s biological record. This paper addresses Africa’s impact crater record and the stratigraphic record of impact cratering, and examines both the challenge that humanity is experiencing from huge extraterrestrial bolides and the benefits that impact has brought. In the end, the conclusion is derived that an integrated geoscientific and planetological science approach has resulted in new tools to address the ultimate questions of Earth’s – and our – past and future.