A killer underneath? Linking petrology and paleoclimate

Magmas and the gases they release link Earth’s interior to surface climate and environments. Examples range in scale from brief sulfur-driven cooling in the wake of explosive eruptions to major mass extinctions in the case of some of the voluminous magmatic episodes known as Large Igneous Provinces.  However, the size of an eruption is only loosely correlated with the severity of its climate consequences, because processes in the mantle, magma storage/transport system, and atmosphere mediate the scale of outgassing and the climate response. Erupted deposits, considered in isolation, often provide an incomplete record of gas release that is apparently at odds with climate archives. In this talk, I demonstrate how the petrology of large-scale magmatic systems can be reconciled with contemporaneous climate proxies. Specifically, I will discuss: 1) uneven global climate disruption from the ~74ka Younger Toba Tuff and implications for early humans, 2) carbon release from the ~66 Ma Deccan Traps and implications for climate on the eve of the Cretaceous-Paleogene mass extinction, 3) suppressed sulfur release from Ontong Java, Earth’s largest known volcanic event, and 4) the role of cryptic outgassing in shaping recovery in the wake of volcanic outpourings.

Speaker: Ben Black, Rutgers University