Fig. 7. Interpretations of pore water biogeochemical processes, lake physiochemistry and solute provenance of the Ries crater lake based on observations from this study. TSR: thermochemical sulfate reduction; MSR: microbial sulfate reduction; MOX: aerobic methane oxidation. The gypsum pseudomorphs in the clay member were reported by Arp et al. (2017) and in basal member by Jankowski (1981); thiophenes in clinoptilolite smbr was reported by Barakat and Rullk¨otter (1997) otherwise in this study; occurrences of diatoms by (Schauderna, 1983). The estimated lake level curve is based on sedimentological observations (e.g. lamination, bioturbation, slumping, mud cracks, in-situ brecciation) in this study and diatom associations in drill core N¨ordlingen 1973 (Schauderna, 1983). The estimated salinity was depicted schematically from indicative organic compounds (Zhao et al., 2022a). The δ15N values schematically correlate with lake water pH variations, with support from hydrochemical modeling results (Stüeken et al., 2020). S isotope data of sedimentary sulfides from drill core N¨ordlingen 1973 were adopted and modified from Tino et al. (2023).