title: Atmospheric PCO₂ perturbations associated with the Central Atlantic Magmatic Province.
abstract: The effects of a large igneous province on the concentration of atmospheric carbon dioxide (PCO₂) are mostly unknown. In this study, we estimate PCO₂ from stable isotopic values of pedogenic carbonates interbedded with volcanics of the Central Atlantic Magmatic Province (CAMP) in the Newark Basin, eastern North America. We find pre-CAMP PCO₂ values of ~2000 parts per million (ppm), increasing to ~4400 ppm immediately after the first volcanic unit, followed by a steady decrease toward pre-eruptive levels over the subsequent 300 thousand years, a pattern that is repeated after the second and third flow units. We interpret each PCO₂ increase as a direct response to magmatic activity (primary outgassing or contact metamorphism). The systematic decreases in PCO₂ after each magmatic episode probably reflect consumption of atmospheric CO₂ by weathering of silicates, stimulated by fresh CAMP volcanics.
authors.affiliation: Department of Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 08854, USA. schaller@rci.rutgers.edu
authors.forename: Morgan F
authors.initials: MF
authors.lastname: Schaller
authors.forename: James D
authors.initials: JD
authors.lastname: Wright
authors.forename: Dennis V
authors.initials: DV
authors.lastname: Kent