Using Novel Geochemical Proxies to Correlate the Volcanic Atmospheric Input of the North Atlantic Igneous Province (NAIP) at the Paleocene – Eocene Thermal Maximum (PETM)

Large Igneous Provinces (LIPs) have caused significant environmental perturbations, including global warming and oceanic anoxia. At least five mass extinction events throughout Earth’s history temporally coincide with the occurrence of LIPs. Geochemical proxies for volcanism in sediments deposited at the time of LIP events can potentially link the volcanic record with the record of environmental change and extinction at <10 ky timescales. Previous studies have used mercury (Hg) enrichments in sediments as a proxy for past volcanism. However, mercury concentrations are sensitive to alteration, the presence of organic matter, and can be enriched in detrital minerals, e.g. pyrite.

We present ICP-MS trace element data from the Fur section in Denmark, where ash layers related to NAIP volcanism are interbedded with sediments deposited immediately after the PETM carbon isotope excursion. Systematic differences in trace element concentrations between ash layers and sediments indicate the potential value of arsenic (As), antimony (Sb), tellurium (Te), rhenium (Re), and thallium (Tl) as volcanic proxies. These elements are enriched in the sediment layers compared to the ashes and correlate with Hg/TOC. In particular, we observe elevated concentrations in Te (up to 600 ppb), compared to the average continental crustal value of about 3 ppb. Leaching of samples with dilute acid suggests that ash particles have degassed Te during eruption, whereas the sediments which were deposited more slowly, incorporate Te in a loosely bound form consistent with an atmospheric origin. We conclude that these trace elements are valuable proxies for the reconstruction of past volcanism.