Zircon dating ties NE Atlantic sill emplacement to initial Eocene global warming

The Earth experienced rapid greenhouse gas induced global warming during the Palaeocene–Eocene thermal maximum (PETM). The source of the gas is, however, debated. We have, for the first time, determined the ages of magmatic sills in the Vøring Basin offshore Norway. Zircon U–Pb ages of 55.6 ± 0.3 and 56.3 ± 0.4 Ma demonstrate that sill emplacement was synchronous with the PETM within small errors. This discovery strengthens the hypothesis that global warming was triggered by rapid release of greenhouse gases generated by heating of organic-rich sediments around intrusions in the NE Atlantic rather than from dissociation of gas hydrates.