Evidence of explosive hydromagmatic eruptions during the emplacement of the North Atlantic Igneous Province

Abstract

Early Eocene sediments in northwest Denmark contain over 180 well-preserved volcanic ash layers, likely sourced from the North Atlantic Igneous Province (NAIP) between 56.0 and 54.6 Ma. Most of these ashes are basaltic, widespread, and represent a phase of unusually large and explosive eruptions that is coincident with the opening of the northeast Atlantic Ocean. Explosive basaltic eruptions of this magnitude are unheard of in historical times and in the current geological record. Here, we combine analyses of glass sulfur concentrations and variations in the morphology and vesicularity of pristine volcanic glass grains to explore the possible eruptive processes promoting such widespread basaltic ash dispersal. We suggest that these ashes formed in shallow subaqueous environments (<200 m water depth) where they fragmented and rapidly quenched during explosive hydromagmatic activity. We speculate that magma-water interaction during the opening of the northeast Atlantic Ocean was the main cause of this unusual explosive basaltic activity.

Rapid and sustained environmental responses to global warming: the Paleocene–Eocene Thermal Maximum in the eastern North Sea

“…Several 12 C-enriched carbon sources may have contributed to the PETM CIE: the dissociation of methane clathrates (Dickens et al, 1995), a bolide impact activating terrestrial carbon reservoirs (Kent et al, 2003;Schaller et al, 2016), and volcanic and thermogenic degassing from the North Atlantic Igneous Province (NAIP; Fig. 1; Eldholm and Thomas, 1993;Svensen et al, 2004;Storey et al, 2007a).…”

“…Located in a likely downwind direction and within proximity to the NAIP, Denmark was also ideally placed to record the contemporary volcanic activity from the NAIP (Fig. 1) that lasted between ∼ 63-54 Ma (Jones et al, 2019;Stokke et al, 2020b;Wilkinson et al, Abdelmalak et al, 2016, Horni et al, 2017, and Jones et al, 2019. The orange dot notes the position of core 22/10a-4 described by Kender et al (2012) and Kemp et al (2016).…”

“…2;Bøggild, 1918;Knox and Morton, 1988;Larsen et al, 2003). The NAIP importance in the PETM initiation and termination is a topic of much discussion (Svensen et al, 2004;Jolley and Widdowson, 2005;Storey et al, 2007a;Frieling et al, 2016;Saunders, 2016;Gutjahr et al, 2017;Jones et al, 2019). To refine this relationship, better constraints on the relative timings of volcanic activity and climatic and environmental changes are needed.…”

Volatile metal emissions from volcanic degassing and lava–seawater interactions at Kīlauea Volcano, Hawai’i

“…Further, our results highlight the unique metal signature of lava-seawater interaction plumes, which would have occurred throughout Earth's history during: oceanic plateau basalt eruptions [28][29][30][31][32][33][34][35] , continental flood basalt eruptions that reached coastlines 26,27 and the early stages of continental rifting 34,35 . Degassing of trace metals from late-stage lava flows at chlorinerich ocean entries, where melts are enriched in Cl over S due to fractional degassing [66][67][68][69] , produces a fundamentally different fingerprint of trace metals to magmatic plumes.…”

“…Basaltic ocean island volcanoes, such as those found on the Island of Hawai'i, can produce an additional source of gas and PM emissions as lava flows reach coastlines and rapidly boil and evaporate seawater, with significant implications for the marine biosphere 25 . Lava-seawater interactions, which produce acidic 'laze' plumes, have occurred throughout Earth's history, often associated with some of the most dramatic manifestations of volcanism, such as: when lava flows from continental flood basalts reached coastlines (e.g., Columbia River Basalt group 26 , Deccan Traps 27 ); in periods of sub-aerial eruption during ocean plateau basalt emplacement (e.g., the Kerguelen 28 , Ontong Java [29][30][31] , and Manihiki 32,33 Plateaus); and during the early stages of continental rifting 34 (e.g., the North Atlantic Igneous Province 35 ). Fragments of silicate material can be generated during lava-seawater interactions through a fuel-coolant-type interaction 36 as seawater invades lava tubes, and during the collapse of lava deltas 37 .…”