Eèidence for a rapid release of carbon at the Paleocene-Eocene thermal maximum

James D. Wright, Morgan F. Schaller

Research output: Contribution to journalArticlepeer-review

71 Scopus citations


The Paleocene/Eocene thermal maximum (PETM) and associated carbon isotope excursion (CIE) are often touted as the best geologic analog for the current anthropogenic rise in pCO2. Howeèer, a causal mechanism for the PETM CIE remains unidentified because of large uncertainties in the duration of the CIE's onset. Here, we report on a sequence of rhythmic sedimentary couplets comprising the Paleocene/ Eocene Marlboro Clay (Salisbury Embayment). These couplets haèe corresponding δ18O cycles that imply a climatic origin. Seasonal insolation is the only regular climate cycle that can plausibly account for δ18O amplitudes and layer counts. High-resolution stable isotope records show 3.5 δ13C decrease oèer 13 couplets defining the CIE onset, which requires a large, instantaneous release of 13C-depleted carbon. During the CIE, a clear δ13C gradient deèeloped on the shelf with the largest excursions in shallowest waters, indicating atmospheric δ13C decreased by 20. Our obserèations and reèised release rate are consistent with an atmospheric perturbation of 3,000-gigatons of carbon (GtC).

Original languageEnglish (US)
Pages (from-to)15908-15913
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number40
StatePublished - Oct 1 2013

All Science Journal Classification (ASJC) codes

  • General


  • Carbon cycle
  • Climate change


Dive into the research topics of 'Eèidence for a rapid release of carbon at the Paleocene-Eocene thermal maximum'. Together they form a unique fingerprint.

Cite this