During the cleaning of the HPC core surfaces from Hole 480 for photography, the material removed was conserved carefully in approximately 10 cm intervals (by K. Kelts); this material was made available to us in the hope that it would be possible to obtain oxygen isotope stratigraphy for the site. The samples were, of course, somewhat variable in size, but the majority were probably between 5 and 10 cm**3. Had this been a normal marine environment, such sample sizes would have contained abundant planktonic foraminifers together with a small number of benthics. However, this is clearly not the case, for many samples contained no foraminifers, whereas others contained more benthics than planktonics. Among the planktonic foraminifers the commonest species are Globigerina bulloides, Neogloboquadrina dutertrei, and N. pachyderma. A few samples contain a more normal fauna with Globigerinoides spp. and occasional Globorotalia spp. Sample 480-3-3, 20-30 cm contained Globigerina rubescens, isolated specimens of which were noted in a few other samples in Cores 3,4, and 5. This is a particularly solution-sensitive species; in the open Pacific it is only found widely distributed at horizons of exceptionally low carbonate dissolution, such as. the last glacial-to-interglacial transition.
Sediment depth is given in mbsf. The analyses with # were made immediately after a machine breakdown; it seems likely, in the light of their plotted position in Figure 1, that they are unreliable. It is our normal procedure to vacuum-roast samples immediately before analysis (in batches of 10 samples); these samples had been roasted before the machine breakdown, which was only fully cured after three weeks. We suspect that vacuum-roasting may decompose a small percentage of the calcite of the foraminifers to CaO, which would be expected to take up atmospheric moisture and CO2 to give a small amount of carbonate of a different isotopic composition. Whether or not this is the correct explanation, we consider that the asterisked analyses should be disregarded.
Supplement to: Shackleton, Nicholas J; Hall, Michael A (1982): Oxygen isotope study of continuous scrape samples from Site 480. In: Curray, JR; Moore, DG; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 64, 1251-1254
