Quantifying mantle carbon fluxes during NAIP emplacement using trace element proxies and high-precision Ar–Ar geochronology

Large Igneous Provinces (LIPs) represent major sources of volcanic CO2 to the Earth system and are widely linked to the past climate perturbations [1]. However, robust quantification of LIP CO2 fluxes remains limited by uncertainties in magma production rates, eruption rates and lack of direct C constraints [2]. Here we present a new approach to reconstructing time- resolved CO2 fluxes during emplacement of the North Atlantic Igneous Province (NAIP) by integrating high-precision 40Ar/39Ar geochronology with geochemical CO2 degassing proxies derived from basaltic lavas.

 

Our methodology builds on recent advances demonstrating systematic relationships between CO₂/S gas ratios, trace element systematics, and mantle melting processes [3.4]. Observed correlation between trace element ratios and inferred CO2/S ratios are used to assess CO2 released for individual lava units. These are combined with modelled eruption volumes and high-precision 40Ar/39Ar age constraints to calculate eruption-rate-scaled CO2 fluxes.

 

This novel approach presented here provides a transferable methodology for reconstructing CO2 flux histories of other LIPs where direct volatile measurement are limited. By coupling high precision geochronology with geochemical degassing proxies, this study generates improved constraints on the links between large-scale volcanism, carbon cycle perturbations, and climate change.

 

LITERATURE:

[1] Kasbohm, J., Schoene, B., & Burgess, S. (2021). Radiometric constraints on the timing, tempo, and effects of large igneous province emplacement. Large igneous provinces: A driver of global environmental and biotic changes, 27-82. [3]

[2] Black, B. A., Neely, R. R., Lamarque, J. F., Elkins-Tanton, L. T., Kiehl, J. T., Shields, C. A., ... & Bardeen, C. (2018). Systemic swings in end-Permian climate from Siberian Traps carbon and sulfur outgassing. Nature Geoscience, 11(12), 949-954. [3] Black, B. A., & Aiuppa, A. (2023). Carbon release from Large Igneous Province magmas estimated from trace element-gas correlations. Volcanica, 6(1), 129-145.

[3] Black, B. A., & Aiuppa, A. (2023). Carbon release from Large Igneous Province magmas estimated from trace element-gas correlations. Volcanica, 6(1), 129-145.

[4] Aiuppa, A., Casetta, F., Coltorti, M., Stagno, V., & Tamburello, G. (2021). Carbon concentration increases with depth of melting in Earth’s upper mantle. Nature Geoscience, 14(9), 697-703.