Stable isotopic values of 174 upper Campanian and Maastrichtian bulk carbonate samples from Demerara Rise, in the western tropical Atlantic (Ocean Drilling Program Leg 207, Sites 1257-1261), largely fall between 0 per mil and 2 per mil for d13C and between -2 per mil and -3 per mil for d18O. The relatively low values and high scatter of d13C values observed suggest secondary calcite with a remineralized organic carbon component was present in most to all samples analyzed. Oxygen isotopic data exhibit less scatter and values closer to those expected for contemporary sea-surface conditions than do carbon data. However, trends in d18O data at any one section do not correlate among sites using shipboard age estimates. Regardless of whether subsequent age estimates modify correlation among holes, diagenetic concerns will remain a significant complication in any efforts to study isotopic trends during the late Campanian-Maastrichtian at these sites.

Depth, sediment is given in mbsf.

Supplement to: MacLeod, Kenneth G (2006): Data report: Stable isotopic ratios in bulk carbonate from upper Campanian and Maastrichtian samples (Demerara Rise, western tropical North Atlantic). In: Mosher, DC; Erbacher, J; Malone, MJ (eds.) Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 207, 1-9