Ries impact structure: Bunte Breccia ejecta resting on scoured, Upper Jurassic limestone

The 26 km-diameter 15 m.y. Ries crater (Nördlinger Ries) in Germany belongs to the few large terrestrial impact structures with a well-preserved ejecta blanket. The multicolored (= bunt) appearance of the ejecta results from an intense mixture of green, dark grey, purple, red and yellowish clays with sandstones of diverse colours, white limestones, rocks from the crystalline basement and even organic material (charcoal; probably from the incorporation of local material upon landing). The Bunte Breccia reflects the major excavation and comprises more than 90% of the ejected material outside the crater rim.
 A  B
Image A shows the typical aspect of the Bunte Breccia in the Gundelsheim quarry 20 km from the center of the structure. In this quarry, the Bunte Breccia is removed little by little to enable the exploitation of the Malmian limestone. Thereby, prominent linear scour marks become visible having originated from the ballistic ejecta emplacement on the competent limestones (Image B). Similar scour marks are exposed all around the Ries crater, and a statistical analysis shows them to pointing radially away from the center of the structure. (Also see Hörz, F. (1982) Ejecta of the Ries Crater, Germany. – Geol. Soc. Am. Special Paper 190, 39-55.).