Methane-Seepage in the Calcareous Alps – Investigating a New Hypothesis for Mass Occurrences of Halorella pedata and Related Brachiopods
Summary
Monospecific brachiopod mass occurrences have been known from the Triassic Hallstatt facies of the Calcareous Alps in Austria for nearly two centuries, but their origin has never been satisfyingly explained.
Our aim is to test the recent hypothesis that such deposits, especially when found in neptunian dikes, represent ancient methane-seep deposits. This hypothesis is based on recent findings of closely related brachiopods at ancient methane-seep deposits in Oregon, USA.
Furthermore, present-day methane seeps in the Gulf of Mexico are typically associated with salt diapirism. Neptunian dikes in the Calcareous Alps are related to diapirism of underlying Permian salts and, therefore, we will focus on mass occurrences of the brachiopods Halorella, Halorelloidea and Sulcirostra that are found in such dikes.
In a second line of research, we will investigate the adaptations of these brachiopods to their environment. Here we will focus on potential adaptations to cope with different fluid flow regimes and predation pressure, which will be assessed by comparing petrographic and geochemical proxies for seepage intensity with size and predation scar pattern among the brachiopods.
This research is funded by FWF – der Wissenschaftsfonds (Austria)
Project Participants at the Museum
External Project Participants
Universität Hamburg, Germany
Universität Wien, Austria
Selected Publications
Kiel, S., Huemer, J., Gussone, N., Berndt, J., Krystyn, L., Zuschin, M., and Peckmann, J. 2021. Brachiopods in early Mesozoic cryptic habitats: Continuous colonization, rapid adaptation, and wide geographic distribution. Palaeogeography, Palaeoclimatology, Palaeoecology 583: 110886.
Kiel, S. and Peckmann, J. 2019. Resource partitioning among brachiopods and bivalves at ancient hydrocarbon seeps: a hypothesis. PLoS ONE 14: e0221887.
Kiel, S., Krystyn, L., Demirtaş, F., Koşun, E., and Peckmann, J. 2017. Late Triassic mollusk-dominated hydrocarbon-seep deposits from Turkey. Geology 45: 751-754.
Kiel, S., Glodny, J., Birgel, D., Bulot, L.G., Campbell, K.A., Gaillard, C., Graziano, R., Kaim, A., Lazar, I., Sandy, M.R., and Peckmann, J. 2014. The paleoecology, habitats, and stratigraphic range of the enigmatic Cretaceous brachiopod Peregrinella. PLoS ONE 9: e109260.