START project Y 58 Studies of Impact Craters Christian KÖBERL 28.06.1996
In the six years that are covered by the START proposal, I would like to work on a variety of topics related to
impact crater research. In the past, impact cratering as a geological process has been rather unappreciated by the
general geological community, despite the fact that on all other planets and satellites with a solid surface, impact
cratering is the most important process that alters the surface at the present time, and during most of the history of
the solar system. Detailed studies, mainly since the 1960s, have led to the recognition of about 150 impact
structures on earth. Over the last 15 years, new studies related to the events that caused the extinction of the
majority of all life on earth at the end of the Cretaceous period led to the hypothesis that a large-scale asteroid or
comet impact occurred 65 Ma ago. The main goal of the studies proposed here would be to engage in
interdisciplinary and international collaborations, to thoroughly study several impact structures from a geochemical,
petrological, mineralogical, and geological point of view, including also aspects of age dating and geophysics. The
type of interdisciplinary research that I envision is similar to the work I have already done (or begun) on, for
example, the Manson structure (Iowa) and the Roter Kamm crater (Namibia); this has been documented in
numerous research publications (see enclosed publication list). Impact crater research is of relevance in the general
earth sciences, as we can learn something about a fundamental process that shapes the surfaces of the terrestrial
planets, including the earth, and because of the observation that some impact events severely affected the
geological and biological evolution on earth; even small impacts can disrupt the biosphere and lead to local
devastation. Thus, the understanding of impact structures and the processes by which they form should be of
interest not only to earth scientists, but also to society in general.