(Table 3) Oxygen isotope ratios of benthic foraminifera from DSDP Hole 80-548, supplement to: Loubere, Paul (1987): Changes in mid-depth North Atlantic and Mediterranean circulation during the Late Pliocene - Isotopic and sedimentological evidence. Marine Geology, 77(1-2), 15-38

• Main Author: Loubere, Paul
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 1987
• Subjects: Sample code/label; Cibicidoides kullenbergi, δ18O; Cibicidoides spp., δ18O; Cibicidoides robertsonianus, δ18O; Globocassidulina subglobosa, δ18O; Uvigerina auberiana, δ18O; Uvigerina peregrina, δ18O; Uvigerina spp., δ18O; Laboratory; Drilling/drill rig; DSDP/ODP/IODP sample designation; Mass spectrometry; Leg80; Glomar Challenger; Deep Sea Drilling Project DSDP; Norwegian Sea; North Atlantic Deep Water; North Atlantic
• Online Access: https://dx.doi.org/10.1594/pangaea.761049; https://doi.pangaea.de/10.1594/PANGAEA.761049

Presently, the intermediate depths of the North Atlantic Ocean are occupied by a great lens of warm, saline water whose source is the Mediterranean Sea. This water flows both westward and northward, finally entering the Norwegian Sea where it may contribute to the formation of North Atlantic Deep Water. The Late Neogene history of Mediterranean Outflow in the Atlantic can be monitored at DSDP-IPOD Site 548 on the continental slope Southwest of Ireland using benthic Foraminifera oxygen isotope values. Isotopic data from 154 samples indicate that Mediterranean water was absent from the mid-depth North Atlantic from 3.4 to 3.2 Ma ago. However, at about 2.9 Ma ago the isotopic values at Site 548 diverge from those recorded from the deep North Atlantic and they can be interpreted to indicate the appearance of a new water mass, possibly Mediterranean water, in the North Atlantic water column. This appearance may be related to climatic changes that occurred around the Mediterranean Basin at about 2.9 Ma ago. The analysis of 189 samples for grain-size distributions shows that a significant increase in the silt-size fraction occurs at the same level that isotopic analysis indicates a change in bottom waters at Site 548. The grainsize data support the hypothesis that mid-depth water-mass changes occurred at about 2.9 Ma ago. : For the age model of DSDP Hole 80-548 see Loubere (1987) data set: doi:10.1594/PANGAEA.761043.