Abtragung der Auswurfdecken, Temperatur-Entwicklung und chemische See-Evolution im Ries-Impakt-Krater

Zusammenfassung der Projektergebnisse

The sediments of the supposed Ries-ejecta-dammed "Rezat-Altmtihl Lake" (Georgensgmtind Formation) are fluviatile deposits and show no evidence of а relation with the Ries event. Accordingly, it is not а mid-Miocene lake dammed up Ьу the Ries impact ejecta. • А volcanic ash layer in the deeper part of the lacustrine succession of the Ries basin, detected for the first time, proves а deep bowl-shaped geometry of the crater fill and а significant crater floor subsidence. А correlation of basin margin carbonates with certain sections of the central basin fill is now comprehensiЬle. • The saline high-alkaline Ries crater lake apparently went through а temporary sulphate-poor phase with methanogenesis, as а result of а shift from sulphate-rich groundwater inflow to sulphate-poorer inflows, with gradual reduction of the sulphate content Ьу sulphate-reducing bacteria. • The Ries crater basin forms а model example for the general chemical and hydrological development of hydrologically closed impact crater lakes of medium size: At first, groundwater inflows from the basement and suevite dominate, later groundwater inflows via fractured megaЬlocks. Only after that, weathering solutions from the primary ejecta cover play а greater role. Finally, very late in the basin development the hydrological catchment area expands, with surface inflows also from outside the crater. • The cooling history of the crater floor with corresponding effects on sedimentation and organism communities in the early Ries crater lake remains to Ье investigated.

Projektbezogene Publikationen (Auswahl)

• A volcanic ash layer in the Miocene Nördlinger Ries impact structure (Germany): Indication of crater fill geometry and long-term crater floor sagging. - GeoMünster, 22-25 September 2019, Münster, abstract #174 [talk]
  Arp, G., Dunkl, I., Hartmann, G., Jung, D., Karius, V., Lukács, R., Reimer, A., Wolff, M. & Head, J.
  
• Sediments of the supposed Ries impact ejecta-dammed "Rezat-Altmühl-Lake" (Miocene, Southern Germany). - GeoMünster, 22-25 September 2019, Münster, abstract #545 [poster]
  Zeng, L., Ruge, D., Berger, G., Heck, K., Hölzl, S., Reimer, A., Jung, D. & Arp, G.
  
• A Volcanic Ash Layer in the Nördlinger Ries Impact Structure (Miocene, Germany): Indication of Crater Fill Geometry and Origins of Long‐Term Crater Floor Sagging. Journal of Geophysical Research: Planets, 126(4).
  Arp, Gernot; Dunkl, István; Jung, Dietmar; Karius, Volker; Lukács, Réka; Zeng, Lingqi; Reimer, Andreas & Head, James W.
  
• Sedimentological and carbonate isotope signatures to identify fluvial processes and catchment changes in a supposed impact ejecta‐dammed lake (Miocene, Germany). Sedimentology, 68(7), 2965-2995.
  Zeng, Lingqi; Ruge, Dag B.; Berger, Günther; Heck, Karin; Hölzl, Stefan; Reimer, Andreas; Jung, Dietmar & Arp, Gernot
  
• Ejecta erosion, hydrological, and chemical lake evolution in the Ries impact basin (Miocene, Germany). - 297 pp., PhD Thesis Georg-August-University of Göttingen
  Zeng L.