Carbon emissions from the North Atlantic Igneous Province: Insights from melt and fluid inclusions in East Greenland

The North Atlantic Igneous Province (NAIP) coincided in time with the Paleocene–Eocene Thermal Maximum (PETM), which is the most recent natural analogue for anthropogenic greenhouse gas emissions [1]. The temporal association between Large Igneous Provinces and climate perturbations throughout the Phanerozoic points to a potential causality via volatile emissions, especially of carbon species. Since East Greenland represents the closest location to the original centre of the mantle plume [2], we studied melt and fluid inclusions within intrusive and effusive rock samples from the (300 km³ sized) Skaergaard intrusion and its overlying (6-8 km thick) Plateau Basalt lava pile to constrain greenhouse gas emissions. Our Raman microspectroscopy data on melt and fluid inclusions hosted in magmatic minerals within these rock samples unveiled the occurrence of different carbon species. In the effusive rock samples, olivine and clinopyroxene phenocrysts host primary melt inclusions containing CO₂ or elemental C within gas bubbles. In the intrusive rock samples, olivine crystals sometimes host CH₄-bearing fluid inclusions, and quartz crystals usually host abundant multiphase (i.e., gaseous ± liquid ± solid phases) fluid inclusions, containing CH₄ and sometimes CO₂ along with H₂O. Volatile species preserved by melt and fluid inclusions within magmatic minerals of Large Igneous Province rocks offer an exceptional window on the magmatic and thermogenic emissions released into the past surface system [3; 4]. Here, we attempt to reconstruct the evolution of carbon speciation throughout the emplacement of intrusive and effusive components of the NAIP across the PETM.

 

[1] Jones et al. (2019), Nat. Commun. 10, 5547.

[2] Larsen & Tegner (2006), Lithos 92, 181–197.

[3] Capriolo et al. (2020), Nat. Commun. 11, 1670.

[4] Capriolo et al. (2021), Nat. Commun. 12, 5534.