Research Article

Atmospheric pCO2 Perturbations Associated with the Central Atlantic Magmatic Province

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Science  17 Feb 2011:
DOI: 10.1126/science.1199011


The effects of a large igneous province on the concentration of atmospheric carbon dioxide (pCO2) are mostly unknown. This study estimates pCO2 from stable isotopic values of pedogenic carbonates interbedded with volcanics of the Central Atlantic Magmatic Province (CAMP) in the Newark Basin. We find pre-CAMP pCO2 values of ~2000 ppm, increasing to ~4400 ppm immediately after the first volcanic unit, followed by a steady decrease over the subsequent 300 kyrs toward pre-eruptive levels, a pattern 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 following each magmatic episode probably reflect consumption of atmospheric CO2 by weathering of silicates, stimulated by fresh CAMP volcanics.