End-Triassic Extinction in a Carbonate Platform From Western Tethys: A Comparison Between Extinction Trends and Geochemical Variations

The Triassic/Jurassic boundary section cropping out at Mt Sparagio in north-western Sicily(Italy) consists of a thick and continuous peritidal succession typical of a Tethyan carbonateplatform. The combined chemostratigraphic and biostratigraphic study of this sectionallowed us to parallel the environmental variations inferred by the isotopic records and theextinction trends recorded by the benthic organisms. In the studied section, the isotopedata of C, O, and S are indicative of serious environmental perturbations related to theCentral Atlantic Magmatic Province (CAMP) activity, as recorded worldwide. Two negativeexcursions in the C-curve (Initial-CIE and Main-CIE) confirm the acidification processes thataffected the benthic community. Moreover, the oxygen isotopes curve indicates a strongwarming-trend that corresponds to the reduction in biodiversity and size of themegalodontoids in the upper part of the Rhaetian beds, probably due to thedeterioration of the photosymbiotic relationships of these pelecypods. We here presentsome novel isotope data (Zn, Pb, Sr) from the Mt Sparagio section that offer additionalclues on a tight control of CAMP volcanism on the End-Triassic Extinction.