Rapid acidification of the ocean during the Paleocene-Eocene thermal maximum.
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.
Zachos
James C
JC
Earth Sciences Department, Earth and Marine Sciences Building, University of California, Santa Cruz, Santa Cruz, CA 95064, USA. jzachos@emerald.uscs.edu
Röhl
Ursula
U
Schellenberg
Stephen A
SA
Sluijs
Appy
A
Hodell
David A
DA
Kelly
Daniel C
DC
Thomas
Ellen
E
Nicolo
Micah
M
Raffi
Isabella
I
Lourens
Lucas J
LJ
McCarren
Heather
H
Kroon
Dick
D