EXAMINING THE COINCIDENCE OF ORGANIC AND CARBONATE CARBON ISOTOPE PERTURBATIONS DURING THE IREVIKEN EXTINCTION EVENT (WENLOCK, SILURIAN)

The Silurian Period (443-416 Ma), part of the early Paleozoic, was marked by a series of three extinction events. The first of these, known as the Ireviken Event (~430 Ma), occurred at the Llandovery-Wenlock boundary. A major perturbation to the global carbon cycle, known as the Ireviken positive carbon isotope excursion, began during Ireviken Event and persisted for much of the early Wenlock. This global carbon cycle perturbation produced a positive carbon isotope excursion in both the organic and carbonate carbon records. However, no paired high-resolution study of both isotope records has been produced through this interval.

To investigate the synchronicity between organic and carbonate carbon, 132 meters of core from Gotland, Sweden, were obtained and organic carbon samples were taken at every 0.5 meter. A total number of 264 organic carbon samples are paired with greater than 500 carbonate carbon samples to precisely define small-scale variations in the ascending and descending limbs of the Ireviken positive isotope excursion.