Palynological evidence of synchronous changes within the terrestrial and marine realm at the Triassic/Jurassic boundary (Csővár section, Hungary)

Abstract

Linking marine and terrestrial events within the end-Triassic extinction is controversial, as is interpretation of carbon cycle perturbation as recorded in carbon isotope excursions. The palynofacies of the Csővár section, Hungary, was studied with the aim of inferring climatic and related vegetation changes within the Triassic/Jurassic boundary interval. The studied section represents a continuous key marine section of the NW Tethyan realm, yielding a typical Late Rhaetian to Hettangian microflora. The most striking feature within the boundary interval is the synchronous peaks of prasinophytes and trilete spores. The co-occurrence of spikes in both the marine and terrestrial signals is described for the first time from a marine boundary section. The prasinophyte and spore peaks also correspond to the previously documented prominent negative carbon isotope excursion and are proposed as a potentially powerful correlation tool. The inferred marine algal bloom and the temporary dominance of ferns in the terrestrial vegetation may signal the biotic response to the same environmental stress, which also affected the carbon cycle. A major perturbation of marine and terrestrial ecosystems is interpreted to be linked to the initial volcanic activity of the Central Atlantic Magmatic Province (CAMP) volcanism.