Hydrothermal vent complexes offshore Northeast Greenland: A potential role in driving the PETM

Abstract

Continental rifting is often associated with voluminous magmatism and perturbations in the Earth's climate. In this study, we use 2D seismic data from the northeast Greenland margin to document two Paleogene-aged sill complexes ≥18 000 and ≥10 000 km2 in size. Intrusion of the sills resulted in the contact metamorphism of carbon-rich shales, producing thermogenic methane which was released via 52 newly discovered hydrothermal vent complexes, some of which reach up to 11 km in diameter. Mass balance calculations indicate that the volume of methane produced by these intrusive complexes is comparable to that required to have caused the negative δ13C isotope excursion associated with the PETM. Combined with data from the conjugate Norwegian margin, our study provides evidence for margin-scale, volcanically-induced greenhouse gas release during the late Paleocene/early Eocene. Given the abundance of similar-aged sill complexes in Upper Paleozoic–Mesozoic and Cretaceous–Tertiary basins elsewhere along the northeast Atlantic continental margin, our findings support a major role for volcanism in driving global climate change. Reynolds, P., et al. "Hydrothermal vent complexes offshore Northeast Greenland: A potential role in driving the PETM." Earth and Planetary Science Letters 467 (2017): 72-78. © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license.