Evidence from U-Th dating against Northern Hemisphere forcing of the penultimate deglaciation
Article Abstract:
It has been possible to date the penultimate deglaciation in a record from the Bahamas using a new U-Th isochron technique. It was established that the midpoint of the penultimate glaciation is 135,200 years, plus or minus 2,500 years. This age is consistent with some coral data. Deglaciation centred at this date is hard to reconcile with an ice-age cycle triggered directly by Northern Hemisphere June isolation, and a more indirect role for changes in isolation must therefore be identified. Modelling indicates that increasing isolation prompts a larger than average number of El Nino/Southern Oscillation warm events, beginning at around 137,000 years ago.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2000
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Direct U-Th dating of marine sediments from the two most recent interglacial periods
Article Abstract:
The direct U-Th dating of aragonite-rich marine sediments gives an accurately dated marine oxygen-isotope record of 120-127 kyr BP for the last interglacial and 189-190 kyr BP for the late stage 7 interglacial. These dates are consistent with the general theory of orbitally forced climate fluctuations. This direct-dating approach establishes an accurate chronology for Pleistocene marine sediments beyond the range of radiocarbon dating. This technique determines the timing of the events, the rate of processes, and the relationship between marine and climatic records.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1996
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Extending the Vostok ice-core record of palaeoclimate to the penultimate glacial period
Article Abstract:
A new glaciological time-scale that is consistent with ocean records has been established for the Vostok station in Antarctica. Ice-core records which reveal local temperature, dust accumulation and air composition extend the glaciological time-scale to the penultimate glacial period, approximately 140,000 to 200,000 years ago. Vostok's penultimate glacial period was colder t the most recent one, and concentrations of carbon dioxide and CH4 correlate well in relation to temperature throughout the record.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1993
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