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.

Sediment depth is given in mcd.

Supplement to: Murphy, Brandi; Lyle, Mitchell W; Olivarez Lyle, Annette (2006): Biogenic burial across the Paleocene/Eocene boundary: Ocean Drilling Program Leg 199 Site 1221. In: Wilson, PA; Lyle, M; Firth, JV (eds.) Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 199, 1-12