Stable isotope record of Cretaceous samples of DSDP Hole 71-511 ...
Oxygen isotope data for upper Turonian planktonic foraminifera at Deep Sea Drilling Project Site 511 (Falkland Plateau, 60°S paleolatitude) exhibit an ~2 per mil excursion to values as low as -4.66 per mil (Vienna Peedee belemnite standard; PDB) coincident with the warmest tropical temperature estim...
| Main Authors: | , , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
PANGAEA
2003
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.1594/pangaea.841771 https://doi.pangaea.de/10.1594/PANGAEA.841771 |
| Summary: | Oxygen isotope data for upper Turonian planktonic foraminifera at Deep Sea Drilling Project Site 511 (Falkland Plateau, 60°S paleolatitude) exhibit an ~2 per mil excursion to values as low as -4.66 per mil (Vienna Peedee belemnite standard; PDB) coincident with the warmest tropical temperature estimates yet obtained for the open ocean. The lowest planktonic foraminifer d18O values suggest that the upper ocean was as warm as 30-32°C. This is an extraordinary temperature for 60°S latitude but is consistent with temperatures estimated from apparently coeval mollusc d18O from nearby James Ross Island (65°S paleolatitude). Glassy textural preservation, a well-defined depth distribution in Site 511 planktonics, low sediment burial temperature (~32°C), and lack of evidence of highly depleted pore waters argue against diagenesis (even solid state diffusion) as the cause of the very depleted planktonic values. The lack of change in benthic foraminifer d18O suggests brackish water capping as the mechanism for the low ... : Supplement to: Bice, Karen L; Huber, Brian T; Norris, Richard D (2003): Extreme polar warmth during the Cretaceous greenhouse? Paradox of the late Turonian d18O record at Deep Sea Drilling Project Site 511. Paleoceanography, 18(2), 1031 ... |
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