Palaeoenvironmental considerations suggest that the continental Miocene Ries-Steinheim impact on the Swabian- Franconian Alb plateau, as a rare case on Earth, affected a region dominated by swamplands and lakes. This is supported by the contemporaneous phreatomagmatism of the nearby Urach Volcanic Field, the widespread occurrence of pre- and early post-impact lacustrine and palustrine sediments that overlie deeply karstifi ed, water-saturated Upper Jurassic target limestones, as well as by a subtropical-humid palaeoclimate and a high groundwater level at the time of impact. The characteristics of the Ries ejecta (e.g. accretionary lapilli) display further evidence. Both impact craters became host to crater lakes soon upon impact. A water-saturated, lacustrine-palustrine phreatic impact scenario is also in agreement with the characteristics of proximal Ries and Steinheim impact ejecta, as well as recent numerical modelling results for the Ries impact. © 2013 E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, Germany.
|Journal||Zeitschrift der Deutschen Gesellschaft fur Geowissenschaften|
|Publication status||Published - 2013|