Developing an experimental approach to define sedimentary degassing from large igneous provinces related and unrelated to mass extinction

Abstract

It is widely thought that major volcanic events can play a key role in triggering biotic crises by introducing climate change volatiles, such as carbon dioxide and sulfur, into the atmosphere. Indeed, several mass extinction events coincide with the emplacement of large igneous provinces(LIPs), but not all LIPs are correlated with an extinction. It has been suggested that LIPs with higher sulfur (S) contents and with CO2- and sulfate-bearing bedrocks are more likely to trigger extinctions. The hypothesis has not been fully tested due to uncertainties in reconstructing original magmatic volatile contents and the volatile budgets of the sediments thermally affected by such magmas. Here, we propose to reconstruct original (undegassed) volatile contents of magmas and sediments via petrological models (by combining chalcophile element systematics and S solubility models to constrain volatile S; partially crystallized and re-homogenized melt inclusions from silicic and tholeiitic rocks to retrieve CO2, Cl, and F contents) and experimental methods (high T experiments in capsules loaded with sedimentary samples from Paraná-Etendeka and CAMP. Results of petrological methods are to be compared with data from three extinction-related LIPs (Siberian Traps, Central Atlantic Magmatic Province, and Deccan Traps). In that way, we intend to answer a longstanding question "What defines the potential of LIPs to promote mass extinctions?". (AU)