23. Biogenic Burial across the Paleocene/Eocene Boundary: Ocean Drilling Program Leg 199 Site 12211

Brandi Murphy,2 Mitchell Lyle,2 and Annette Olivarez Lyle2


The Paleocene/Eocene (P/E) boundary, at ~55 Ma, is characterized by a transient warm period lasting 10,000 yr. This interval is globally characterized by significant chemical and biological signals. Ocean Drilling Program Core 199-1221C-11X captured the P/E boundary section at a depth of 154 meters composite depth. Biogenic components of the sediment were measured across this interval in order to better define the events that occurred at the P/E boundary in the equatorial Pacific Ocean. A 26-cm interval low in CaCO3 was identified, whereas biogenic silica and organic carbon remained unchanged. Although CaCO3, biogenic silica, and organic carbon (C-org) production is controlled by different constraints, it is unlikely that an environmental factor would cease production by CaCO3-producing organisms without affecting biogenic silica or C-org production. The data indicate that the CaCO3 P/E boundary event was caused by a change in CaCO3 preservation rather than a change in CaCO3 production.

1Murphy, B., Lyle, M., and Olivarez Lyle, A., 2006. Biogenic burial across the Paleocene/Eocene boundary: Ocean Drilling Program Leg 199 Site 1221. In Wilson, P.A., Lyle, M., and Firth, J.V. (Eds.), Proc. ODP, Sci. Results,199: College Station, TX (Ocean Drilling Program), 1–12. doi:10.2973/odp.proc.sr.199.215.2006

2Center for the Geophysical Investigation of the Shallow Subsurface, Boise State University, MG206, 1910 University Drive, Boise ID 83725, USA. Correspondence author: murphyb@ucsd.edu

Initial receipt: 19 April 2004
Acceptance: 24 October 2005
Web publication: 16 June 2006
Ms 199SR-215