Linking the PETM and North Atlantic volcanism using tellurium in sediments

Abstract

The Paleocene – Eocene Thermal Maximum (PETM) was a short period (∼170 kyr) of global temperature rise starting at 55.93 Ma, which occurred during the breakup of the North Atlantic and the emplacement of the North Atlantic Igneous Province (NAIP). Recently, mercury (Hg) concentrations in sediments have been used in an attempt to connect the eruptive history of the NAIP with environmental change during this period, at a higher resolution than possible using geochronology. Here we present sedimentary tellurium (Te) as a novel proxy to further reconstruct NAIP volcanism at high resolution. We measured 45 trace elements in 401 sediment samples from 3 sections across the PETM in the northern hemisphere. All study sites exhibit an increase in Te concentrations and Te/Th ratios close to the onset of the PETM and remain high until the end of the main North Atlantic ash phase about 1 Myr later. The trace element data indicate that changes in sediment lithology or in environmental conditions do not influence sedimentary Te concentrations suggesting a volcanic source instead. We used existing age models to remove the effect of changes in sedimentation rate and calculated volcanic Te fluxes. Our Te data suggest increased volcanism in the latest Paleocene and early Eocene. This fits existing radiometric ages of the NAIP, which demonstrate that a more than 5 km thickness of lava in eastern Greenland and the Faroes was erupted within about 1 Myr between ∼56 to ∼55 Ma. All our study sites show similar Te flux variations across the PETM. In contrast, sedimentary mercury (Hg) profiles from these and other sites are less consistent. Tellurium in sediments may represent a useful proxy to reconstruct NAIP volcanism.