Berberich, G.M.; Berberich, M.B. Comparison of geogases in Cenozoic sedimentary environments. Preprints2022, 2022090149. https://doi.org/10.20944/preprints202209.0149.v1
APA Style
Berberich, G.M., & Berberich, M.B. (2022). Comparison of geogases in Cenozoic sedimentary environments. Preprints. https://doi.org/10.20944/preprints202209.0149.v1
Chicago/Turabian Style
Berberich, G.M. and Martin B. Berberich. 2022 "Comparison of geogases in Cenozoic sedimentary environments" Preprints. https://doi.org/10.20944/preprints202209.0149.v1
Abstract
We investigated fault gases (helium, radon, CO2) in two seismically active Cenozoic sedimentary environments: a) Meinweg (in 2015) at a tectonically quiet horst structure in the Lower Rhine Embayment and b) Bodanrück (in 2012; Lake of Constance) at the Molasse Basin and part of the Freiburg–Bonndorf–Bodensee Fault Zone (FBBFZ). Both study areas were selected because recent “GeoBio-Interactions” findings showed, that red wood ants (RWA) are biological indicators of otherwise undetected degassing systems. A total of 817 soil gas samples was analyzed. Currently, Meinweg can be considered “no ants land” due to the very low background-level geogas concentrations. Thus, anomalies (Rn-CO2) weakly trending in NE-SW extension direction emerged. This could probably indicate the onset of (re)activation of the NE-SW trending (Variscan) structures or the development of new fractures as an aftershock process of the 1992 Roermond earthquake that occurred about 15 km to the west. Results at Bodanrück (3 RWA clusters and two RWA-free corridors) revealed degassing patterns in NW-SE and NNE-SSW directions in the clusters corresponding to re-activated and recent strike-slip fault systems. No gas anomalies were found in RWA-free corridors. The RWA nest distribution was shown to be a valuable tool for identifying areas of even actively degassing spotty anomalies caused by macro- and microscale brittle deformation masked by sediment cover.
Keywords
soil gas anomalies; Helium, Radon, CO2; Lower Rhine Embayment (LRE); Meinweg; Roer Valley Rift System (RVRS); Molasse Basin; Bodanrück; Freiburg–Bonndorf–Bodensee Fault Zone (FBBFZ); GeoBio-Interactions
Subject
Environmental and Earth Sciences, Geochemistry and Petrology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
