title: Rapid acidification of the ocean during the Paleocene-Eocene thermal maximum.
abstract: The Paleocene-Eocene thermal maximum (PETM) has been attributed to the rapid release of approximately 2000 x 10(9) metric tons of carbon in the form of methane. In theory, oxidation and ocean absorption of this carbon should have lowered deep-sea pH, thereby triggering a rapid (<10,000-year) shoaling of the calcite compensation depth (CCD), followed by gradual recovery. Here we present geochemical data from five new South Atlantic deep-sea sections that constrain the timing and extent of massive sea-floor carbonate dissolution coincident with the PETM. The sections, from between 2.7 and 4.8 kilometers water depth, are marked by a prominent clay layer, the character of which indicates that the CCD shoaled rapidly (<10,000 years) by more than 2 kilometers and recovered gradually (>100,000 years). These findings indicate that a large mass of carbon (>>2000 x 10(9) metric tons of carbon) dissolved in the ocean at the Paleocene-Eocene boundary and that permanent sequestration of this carbon occurred through silicate weathering feedback.
authors.affiliation: Earth Sciences Department, Earth and Marine Sciences Building, University of California, Santa Cruz, Santa Cruz, CA 95064, USA. jzachos@emerald.uscs.edu
authors.forename: James C
authors.initials: JC
authors.lastname: Zachos
authors.forename: Ursula
authors.initials: U
authors.lastname: Röhl
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Schellenberg
authors.forename: Appy
authors.initials: A
authors.lastname: Sluijs
authors.forename: David A
authors.initials: DA
authors.lastname: Hodell
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Kelly
authors.forename: Ellen
authors.initials: E
authors.lastname: Thomas
authors.forename: Micah
authors.initials: M
authors.lastname: Nicolo
authors.forename: Isabella
authors.initials: I
authors.lastname: Raffi
authors.forename: Lucas J
authors.initials: LJ
authors.lastname: Lourens
authors.forename: Heather
authors.initials: H
authors.lastname: McCarren
authors.forename: Dick
authors.initials: D
authors.lastname: Kroon