Palaeoenvironmental variability and carbon cycle perturbations during the Smithian-Spathian (Early Triassic) in Central Spitsbergen

• Main Authors: Blattmann, Franziska R, Schneebeli-Hermann, Elke, Adatte, Thierry, Bucher, Hugo F R, Vérard, Christian, Hammer, Øyvind, Luz, Zoneibe A S, Vennemann, Torsten W
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley-Blackwell Publishing, Inc. 2024
• Subjects: Department of Paleontology; 560 Fossils & prehistoric life; Barents Sea; Spitsbergen
• Online Access: https://www.zora.uzh.ch/id/eprint/260551/; https://www.zora.uzh.ch/id/eprint/260551/1/Blattmann_et_al_2024___palaeoenvironmental_variability_and_carbon_cycle_perturbations_.pdf; https://www.idunn.no/doi/10.18261/let.57.2.1; https://doi.org/10.5167/uzh-260551; https://doi.org/10.18261/let.57.2.1

The Early Triassic Smithian and Spathian time intervals are characterized by perturbations in the global carbon cycle, fluctuations in sea surface temperature, high turnover rates of marine nekton, and a change in terrestrial vegetation. Despite the importance of this time interval, comprehensive multiproxy investigations from Early Triassic high and middle latitude regions remain scarce due to the difficulty in accessing sections. The objective of this study is to increase our understanding of regional and local palaeoenvironmental and carbon cycle perturbations from a middle Smithian to late Spathian middle latitude section from Central Spitsbergen. Geochemical analyses show an increase in phosphorus and nitrogen just at and above the Smithian–Spathian boundary (SSB). High primary productivity led to increasingly anoxic conditions in bottom waters during the middle and late Spathian, enhancing the preservation of organic matter in the sediments. Anoxic conditions restrain phosphorus remineralization, allowing it to be recycled within the water column. This increase in anoxia is consistent with observations in other Arctic basins, demonstrating larger regional similarities in palaeoenvironmental conditions. The fluctuations in isostatic and eustatic sea levels affected organic carbon sequestration by regulating organic matter mineral interactions via the control of grain size within the sediment. This study demonstrates that local organic carbon sequestration in the Barents Sea shelf during the Spathian was influenced by a multitude of factors, including sedimentology, redox conditions, nutrient availability, and primary productivity. □ Vikinghøgda Formation, bulk rock geochemistry, particulate organic matter, extinction recovery, carbon isotopes, Stensiöfjellet Franziska R. Blattmann ✉ [[e-mail]], Zoneibe A.S. Luz [[e-mail]] and Torsten W. Vennemann [[e-mail]], Institute of Earth Surface Dynamics, University of Lausanne, Quartier UNIL-Mouline, 1015 Lausanne, ...