Stable isotope ratios measured on molluscan from the CRP sediment cores in the Ross Sea, Antarctica

Stable isotope analyses of marine bivalve growth increment samples have been used to estimate early Oligocene (29.4 - 31.2) Ma and early Miocene (24.0 Ma) seafloor palaeotemperature from the southwestern continental margin of the Ross Sea. Measured d18O values average +2.5 ‰ in the early Miocene and...

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Bibliographic Details
Main Authors: Lavelle, Mark, Fielding, Christopher R, Hall, Michael A
Format: Dataset
Language:English
Published: PANGAEA 2001
Subjects:
14.2 km at 096° true from Cape Roberts
Cape Roberts Project
Core wireline system
CRP
CRP-2
CRP-3
CWS
off Cape Roberts
Ross Sea
Antarctica
Sampling/drilling from ice
Cape Roberts
McMurdo Sound
Roberts Cape
Antarc*
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.510768
https://doi.org/10.1594/PANGAEA.510768
Description
Summary:Stable isotope analyses of marine bivalve growth increment samples have been used to estimate early Oligocene (29.4 - 31.2) Ma and early Miocene (24.0 Ma) seafloor palaeotemperature from the southwestern continental margin of the Ross Sea. Measured d18O values average +2.5 ‰ in the early Miocene and range between +1.26 to +3.24 ‰ in the early Oligocene. The results show that palaeoceanographic conditions in McMurdo Sound during the mid-Cenozoic were significantly different from those of today. The minimum estimated spring through late summer seasonal temperature range was 3°C during the early Miocene and between 1 and 5°C during the early Oligocene. This compares to the equivalent modern day range of <0.5°C within the sound. Absolute seawater temperatures at <100 m depth were of the order of 5 to 7°C during both time slices, compared to modern day values of -1.4 to - 1.9°C in the same area. The results are in broad agreement with early Oligocene Mg/Ca temperature estimates from deep Atlantic foraminifera as well as estimates from local terrestrial palynology and palaeobotany.

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