(Table T1) Stable carbon isotopic composition of n-alkanes and carbon preference index of ODP Hole 208-1263A@en

Carbon isotope ratios of terrestrial biomarkers extracted from Ocean Drilling Program Hole 1263A show a prominent negative excursion across the Paleocene/Eocene boundary. The isotope profiles of the normal alkanes nonacosane (n-C29), hentriacontane (n-C31), and tritriacontane (n-C33), the first such profiles generated with samples from a pelagic section, are similar to those of carbonate carbon, though the magnitude of the excursion is larger, roughly 4-5. In addition, the n-alkane records show an inflection at 334.70 meters composite depth, which is roughly equivalent to where the inflection occurs in the carbonate record. These results suggest that the terrestrial compounds are directly recording changes in atmospheric carbon 13C and that the actual excursion may have been larger than that recorded by marine carbonates.