Thermogenic carbon release from the Central Atlantic magmatic province caused major end-Triassic carbon cycle perturbations

Significance The Central Atlantic magmatic province (CAMP) is coincident with the end-Triassic extinction event and several negative carbon isotope excursions (CIEs). Sill emplacements in Brazil would have generated extensive volatiles and degassing due to the contact metamorphism of evaporites, organic-rich shales, and hydrocarbons. Thermogenic carbon release from contact metamorphism represents a plausible source for 12 C; however, this has not yet been explored from a carbon cycle approach. This study explores the effects of thermogenic carbon release from CAMP using carbon cycle modeling and shows that it represents a credible source for the negative CIEs at the end-Triassic. It strengthens the hypothesis that the subvolcanic part of a large igneous province is of major importance for understanding carbon cycle disruptions.