Spatial and Temporal Offsets between Proxy Records in a Sediment Drift

Chronologies for Late Quaternary marine sediment records are usually based on radiocarbon ages of planktonic foraminifera. Signals carried by other sedimentary components measured in parallel can provide complementary paleodimate information. A key premise is that microfossils and other indicators w...

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Bibliographic Details
Published in:Science (American Association for the Advancement of Science) 2002-11, Vol.298 (5596), p.1224-1227
Main Authors: Ohkouchi, Nao, Eglinton, Timothy I., Keigwin, Lloyd D., Hayes, John M.
Format: Article
Language:English
Subjects:
Calibration
Carbonates
Climate proxies
Drift
Earth sciences
Earth, ocean, space
Exact sciences and technology
Foraminifera
Glacial deposits
Haptophyta
Marine
Marine and continental quaternary
Marine geology
Oceans
Paleoclimatology
Proxy reporting
Proxy statements
Radiocarbon
Sediments
Sediments (Geology)
Surface water
Surficial geology
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Summary:Chronologies for Late Quaternary marine sediment records are usually based on radiocarbon ages of planktonic foraminifera. Signals carried by other sedimentary components measured in parallel can provide complementary paleodimate information. A key premise is that microfossils and other indicators within a given sediment horizon are of equal age. We show here that haptophyte-derived alkenones isolated from Bermuda Rise drift sediments are up to 7000 years older than coexisting planktonic foraminifera. This temporal offset, which is apparently due to lateral transport of alkenones on fine-grained particles from the Nova Scotian margin, markedly influences molecular estimates of sea surface temperatures. More broadly, the observation raises questions about both the temporal and the geographic fidelity of paleoenvironmental records encoded by readily transported components of sediments.
ISSN:0036-8075
1095-9203
DOI:10.1126/science.1075287