;
• Ridgwell, A.
;
• Kump, L. R.

Abstract

Possible sources of carbon that may have caused global warmingat the Paleocene-Eocene boundary are constrained using an intermediatecomplexity Earth-system model configured with early Eocene paleogeography.We find that 6800 Pg C (<IMG SRC="/math/delta.gif" ALT="{delta}" BORDER="0">¹³C of -22<IMG SRC="/math/permil.gif" ALT="{per thousand}" BORDER="0">) is the smallest pulsemodeled here to reasonably reproduce observations of the extentof seafloor CaCO₃ dissolution. This pulse could not have beensolely the result of methane hydrate destabilization, suggestingthat additional sources of CO₂ such as volcanic CO₂, the oxidationof sedimentary organic carbon, or thermogenic methane must alsohave contributed. Observed contrasts in dissolution intensitybetween Atlantic and Pacific sites are reproduced in the modelby reducing bioturbation in the Atlantic during the event, simulatinga potential consequence of the spread of low-oxygen bottom waters.