Palynological insights into the Carnian Pluvial Episode (CPE) in Switzerland

The Carnian Pluvial Episode (CPE), dated to 234-232 Ma, marks a major climatic disruption during the Late Triassic, interrupting the prevailing arid conditions in the paleotropics with increased humidity. The CPE coincided with key evolutionary events in the marine and terrestrial realms. In the Central European Basin, this shift is recorded by a rise in siliciclastic sedimentation, notably in the Ergolz Member (‘Schilfsandstein’) of the Klettgau Formation. We present palynological and bulk organic carbon isotope data from the Bözberg core, in northern Switzerland. Palynological data indicate an organic matter input predominantly of terrestrial origin, with well-preserved assemblages. Althought spore diversity is low, sporomorphs offer valuable insights into regional paleoenvironmental changes. Qualitative and quantitative analyses reveal a shift from xerophytic to hygrophytic assembalges, accompanied by an increase in spore abundance, suppporting evidence for changing climatic conditions during the CPE in this region. A notable feature is the occurence of Aulisporites astigmosus, a taxon associated with humid intervals during the CPE in Tethyan records (Baranyi et al., 2018).

References :

Baranyi, V., Miller, S. V., Ruffell, A., Hounslow, W., M. & Kürschner, M. W. 2018: A continental record of the Carnian Pluvial Episode (CPE) from the Mercia Mudstone Group (UK): palynology and climatic implications, Journal of the Geological Society, 176, 149-166.