In early April, some of the University of Manchester Planetary Geology pathway students in their 3rd year took a trip to explore the formation and geology of Ries Crater in southern Germany. The group stayed in the quaint Bavarian town of Nördlingen, which is about the same size (~1 km in diameter) as the impactor which formed the crater. Ries crater formed ~14.8 million years ago (Schwarz et al., 2020) from the collision of an extra-terrestrial impactor. The resulting explosion from the impact event likely rivalled the power of 250 000 atomic bombs (Böhme et al., 2002), obliterating all life within a radius of 100 000 km. The site has been popular as an analogue for training astronauts and was visited by Apollo 14 astronauts Alan Shepard and Edgar Mitchel in 1970.
The group started off looking at the suevite, a rock type which is famous for only being found at Ries crater. Suevite is an impactite, a rock which is formed from deposition during the impact event. The town church (St. George’s church) is famous for being built out of suevite. The group were then taken to various field sites and quarries, where different impact rock types were exposed, including the famous ‘bunte’ breccia – Bunt means colourful in German, these deposits originate from different rock formations of different colours, hence appear colourful.
The group prevailed through various weather conditions, both very hot and very cold and windy, with only minor sunburns, and lots of rocks (especially shatter cones) as bounties for their efforts.
References
Böhme, M., Gregor, HJ., Heissig, K. (2002). The Ries and Steinheim Meteorite Impacts and their Effect on Environmental Conditions in Time and Space. In: Geological and Biological Effects of Impact Events (eds. Buffetaut, E., Koeberl, C.). Impact Studies. Springer, Berlin, Heidelber.
Sagy, A., Fineberg, J., Reches, Z. (2004). “Shatter cones: Branched, rapid fractures formed by shock impact”. Journal of Geophysical Research. 109 (B10): B10209.
Schwarz, W. H., Hanel, M., Trieloff, M. (2020). U‐Pb dating of zircons from an impact melt of the Nördlinger Ries crater. Meteoritics & Planetary Science. 55 (2): 312–325