Stable carbon and oxygen isotope ratios of benthic foraminifera from Paleocene to Oligocene sediments ...

• Main Authors: Kennett, James P, Stott, Lowell D
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 1990
• Subjects: Drilling/drill rig; Leg113; Joides Resolution; Ocean Drilling Program ODP; Antarc*; Antarctic; Antarctica
• Online Access: https://dx.doi.org/10.1594/pangaea.726317; https://doi.pangaea.de/10.1594/PANGAEA.726317

Benthic oxygen and carbon isotopic results from a depth transect on Maud Rise, Antarctica, provide the first evidence for Warm Saline Deep Water (WSDW) in the Paleogene oceans. Distinct reversals occur in the oxygen isotopic gradient between the shallower Hole 689B (Eocene depth ~1400 m; present-day depth 2080 m) and the deeper Hole 690B (Eocene depth ~2250 m; present-day depth 2914 m). The isotopic reversals, well developed by at least 46 Ma (middle middle Eocene), existed for much of the remaining Paleogene. We do not consider these reversals to be artifacts of differential diagenesis between the two sites or to have resulted from other potentially complicating factors. This being so, the results show that deep waters at Hole 690B were significantly warmer than deep waters at the shallower Hole 689B. A progressive decrease and eventual reversal in benthic to planktonic delta18O gradients in Hole 690B, demonstrate that the deeper waters became warmer relative to Antarctic surface waters during the Eocene. ... : For age models see Stott et al. (1990) datasets: doi:10.1594/PANGAEA.726370 ...