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 ∼2000 × 109 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 × 109 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.
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We thank the ODP Leg 208 Science Crew for their contributions and C. John and S. Bohaty for technical assistance. The ODP supplied samples. Supported by NSF grant EAR-0120727 to J.C.Z. and E.T. and by DFG grant no. Ro 1113/3 to U.R.
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Science
Volume 308 | Issue 5728
10 June 2005
10 June 2005
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American Association for the Advancement of Science.
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Received: 21 December 2004
Accepted: 18 April 2005
Published in print: 10 June 2005
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