A widespread pronounced enrichment in the organic carbon content occurs at shallow depths in eastern equatorial Pacific sediments. The Corg peak is shown by radiocarbon dating to be temporally coincident with the last (Stage 2 or Wisconsin) glacial maximum. In contrast, CaCO3 profiles show less overall variation, which appears to be partly a function of the location of the sediments relative to the lysocline. Consideration of the iodine:Corg ratio in the sediments rules out enhanced preservation as a cause of the Stage 2 organic carbon enrichment. The peak, instead, must have resulted from a significant increase in productivity during the glacial maximum.