Bolide summer: The Paleocene/Eocene thermal maximum as a response to an extraterrestrial trigger

LDEO Publication: 
Publication Type  Journal Article
Year of Publication  2005
Authors  Cramer, B. S.; Kent, D. V.
Journal Title  Palaeogeography Palaeoclimatology Palaeoecology
Volume  224
Issue  1-3
Pages  144-166
Journal Date  08/2004
ISBN Number  0031-0182
Accession Number  ISI:000231410300008
LDEO Publication Number  6636
Key Words  paleocene/eocene thermal maximum; carbon isotope excursion; bolide impact; methane hydrates; carbon cycle; bioevents; cretaceous-tertiary boundary; carbon-isotope excursion; gas-hydrate; eocene boundary; planktonic-foraminifera; deep-sea; sequence boundar

The standard paradigm that the Paleocene/Eocene thermal maximum (PETM) represents a threshold event intrinsic to Earth's climate and connected in some way with long-term warming has influenced interpretations of the geochemical, climate, and biological perturbations that occurred at this event. As recent high-resolution data have demonstrated that the onset of the event was geologically instantaneous, attempts to account for the event solely through endogenous mechanisms have become increasingly strained. The rapid onset of the event indicates that it was triggered by a catastrophic event which we suggest was most likely a bolide impact. We discuss features of the PETM that require explanation and argue that mechanisms that have previously been proposed either cannot explain all of these features or would require some sort of high-energy trigger. A bolide impact could provide such a trigger and, in the event of a comet impact, could contribute directly to the shape of the carbon isotope curve. We introduce a carbon cycle model that would explain the PETM by global warming following a bolide impact, leading to the oxidation of terrestrial organic carbon stores built up during the late Paleocene. Our intention is to encourage other researchers to seriously consider an impact trigger for the PETM, especially in the absence of plausible alternative mechanisms. (c) 2005 Elsevier B.V. All rights reserved.


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URL  <Go to ISI>://000231410300008
DOI  DOI 10.1016/j.palaeo.2005.03.040