Palaeoenvironmental significance of organic facies and stable isotope signatures: the Ladinian San Giorgio Dolomite and Meride Limestone of Monte San Giorgio (Switzerland, WHL UNESCO)

Monte San Giorgio reveals that its Ladinian carbonate section contains immature organic matter primarily of marine bacterial origin, with increasing land plant-derived contributions upsection. This study links organic-matter accumulation to sea-level changes, productivity, and volcanic activity-induced rainfall. Enhanced productivity during high sea levels contributed to black-shale formation under anoxic-sulphidic conditions, while low sea levels intensified runoff, leading to basin restriction and laminated limestone deposition under dysoxic to anoxic conditions. Benthic microbial activity played a significant role in hydrogen-rich organic matter production, carbonate precipitation, and vertebrate fossil preservation. The research integrates sedimentology, geochemistry, and microscopy to provide insights into palaeoenvironmental dynamics.

Stockar, R., Adatte, T., Baumgartner, P. O., & Föllmi, K. B. (2013). Palaeoenvironmental significance of organic facies and stable isotope signatures: the Ladinian San Giorgio Dolomite and Meride Limestone of Monte San Giorgio (Switzerland, WHL UNESCO). Sedimentology, 60(1), 239–269. Portico. https://doi.org/10.1111/sed.12021