title: Ocean acidification and the Permo-Triassic mass extinction.
abstract: Ocean acidification triggered by Siberian Trap volcanism was a possible kill mechanism for the Permo-Triassic Boundary mass extinction, but direct evidence for an acidification event is lacking. We present a high-resolution seawater pH record across this interval, using boron isotope data combined with a quantitative modeling approach. In the latest Permian, increased ocean alkalinity primed the Earth system with a low level of atmospheric CO2 and a high ocean buffering capacity. The first phase of extinction was coincident with a slow injection of carbon into the atmosphere, and ocean pH remained stable. During the second extinction pulse, however, a rapid and large injection of carbon caused an abrupt acidification event that drove the preferential loss of heavily calcified marine biota.
authors: School of Geosciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3FE, UK. matthew.clarkson@otago.ac.nz.
authors: M O
authors: MO
authors: Clarkson
authors: Faculty of Geosciences and MARUM-Center for Marine Environmental Sciences, University of Bremen, 28334 Bremen, Germany.
authors: S A
authors: SA
authors: Kasemann
authors: School of Geosciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3FE, UK.
authors: R A
authors: RA
authors: Wood
authors: College of Life and Environmental Sciences, University of Exeter, Laver Building, North Parks Road, Exeter EX4 4QE, UK.
authors: T M
authors: TM
authors: Lenton
authors: College of Life and Environmental Sciences, University of Exeter, Laver Building, North Parks Road, Exeter EX4 4QE, UK.
authors: S J
authors: SJ
authors: Daines
authors: Institute of Earth Sciences, NAWI Graz, University of Graz, Heinrichstraße 26, 8010 Graz, Austria.
authors: S
authors: S
authors: Richoz
authors: Faculty of Geosciences and MARUM-Center for Marine Environmental Sciences, University of Bremen, 28334 Bremen, Germany.
authors: F
authors: F
authors: Ohnemueller
authors: Faculty of Geosciences and MARUM-Center for Marine Environmental Sciences, University of Bremen, 28334 Bremen, Germany.
authors: A
authors: A
authors: Meixner
authors: School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK.
authors: S W
authors: SW
authors: Poulton
authors: Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK.
authors: E T
authors: ET
authors: Tipper
mesh_terms: D000818:Animals; D059001:Aquatic Organisms; D001272:Atmosphere; D001895:Boron; D002244:Carbon; D057486:Carbon Cycle; D002247:Carbon Isotopes; D017753:Ecosystem; D053476:Extinction, Biological; D006863:Hydrogen-Ion Concentration; D007554:Isotopes; D009792:Oceans and Seas; D012623:Seawater / Q000737:chemistry*; D013995:Time
chemical_list: D002247:Carbon Isotopes; D007554:Isotopes; D002244:Carbon; D001895:Boron