RHYTHMIC LAYERING IN THE SUEVITE, AND REWORKED "BUNTE BRESCHE" OF THE OTTING QUARRY, OTTING, BAVARIA, GERMANY: EVIDENCE FOR A DIATREMIC ORIGIN FOR THE RIES BASIN, BAVARIA, GERMANY

The "Bunte Bresche" and suevite section of sedimentary rocks in the Otting quarry (explosion breccia originating from the Noerdlinger Ries 2 miles to the west) were investigated to test the interpretations of impact vs. diatremic origin for the Ries crater. The Bunte Bresche is composed of Mesozoic sedimentary rock fragments and is followed upwards by suevite (melted basement fragments). Evidence: a) the rhythmicity of the layering of the suevite (periodic or cyclic deposition/periodic or pulsating expulsion) which overlies the Bunte Bresche (building stone quarry at Otting); and b) the fine-grained first deposited layers of the Bunte Bresche indicating a time lapse along with reworking by water before the main part of the Bunte Bresche was deposited. Whereas a diatreme may have repetitive action, a meteorite impact will have only one event or action. Therefore, the above evidence supports a diatremic formation for the Ries Basin, also supporting a volcanic-diatremic-tectonic origin for the lineament connecting the Kaiserstuhl volcanics, and, eastwards, the Urach (Swabian) diatremes, Randecker Maar, Steinheim Basin and Ries Basin in the east.