title: Thermal erosion of cratonic lithosphere as a potential trigger for mass-extinction.
abstract: The temporal coincidence between large igneous provinces (LIPs) and mass extinctions has led many to pose a causal relationship between the two. However, there is still no consensus on a mechanistic model that explains how magmatism leads to the turnover of terrestrial and marine plants, invertebrates and vertebrates. Here we present a synthesis of ammonite biostratigraphy, isotopic data and high precision U-Pb zircon dates from the Triassic-Jurassic (T-J) and Pliensbachian-Toarcian (Pl-To) boundaries demonstrating that these biotic crises are both associated with rapid change from an initial cool period to greenhouse conditions. We explain these transitions as a result of changing gas species emitted during the progressive thermal erosion of cratonic lithosphere by plume activity or internal heating of the lithosphere. Our petrological model for LIP magmatism argues that initial gas emission was dominated by sulfur liberated from sulfide-bearing cratonic lithosphere before CO2 became the dominant gas. This model offers an explanation of why LIPs erupted through oceanic lithosphere are not associated with climatic and biotic crises comparable to LIPs emitted through cratonic lithosphere.
authors.affiliation: Institute of Earth Sciences, University of Lausanne, Géopolis, 1015 Lausanne, Switzerland.
authors.forename: Jean
authors.initials: J
authors.lastname: Guex
authors.affiliation: Institute of Earth Sciences, University of Lausanne, Géopolis, 1015 Lausanne, Switzerland.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Pilet
authors.affiliation: Institute of Earth Sciences, University of Lausanne, Géopolis, 1015 Lausanne, Switzerland.
authors.forename: Othmar
authors.initials: O
authors.lastname: Müntener
authors.affiliation: Muséum National d'Histoire Naturelle, CNRS UMR 7207 Paleobiodiversité et Paléoenvironnements, CP38, 8 rue Buffon, F-75005 Paris, France.
authors.forename: Annachiara
authors.initials: A
authors.lastname: Bartolini
authors.affiliation: Institute of Earth Surface Dynamics, University of Lausanne, Géopolis, 1015 Lausanne, Switzerland.
authors.forename: Jorge
authors.initials: J
authors.lastname: Spangenberg
authors.affiliation: Department of Geosciences, Princeton University, 219 Guyot Hall, Princeton, New Jersey 08544, USA.
authors.forename: Blair
authors.initials: B
authors.lastname: Schoene
authors.affiliation: Earth &Environmental Sciences, University of Geneva, Rue des Maraîchers 13, 1205 Geneva, Switzerland.
authors.forename: Bryan
authors.initials: B
authors.lastname: Sell
authors.affiliation: Earth &Environmental Sciences, University of Geneva, Rue des Maraîchers 13, 1205 Geneva, Switzerland.
authors.forename: Urs
authors.initials: U
authors.lastname: Schaltegger
mesh_terms: D002244:Carbon / Q000032:analysis*; D002980:Climate; D053476:Extinction, Biological; D019015:Geologic Sediments / Q000032:analysis*; D017752:Greenhouse Effect; D010100:Oxygen / Q000032:analysis*; D013696:Temperature
chemical_list: D002244:Carbon; D010100:Oxygen