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Reconstruction of deglacial sea surface temperatures in the tropical Pacific from selective analysis of a fossil coral
Author(s) -
Allison Nicola,
Finch Adrian A.,
Tudhope Alexander W.,
Newville Matthew,
Sutton Stephen R.,
Ellam Robert M.
Publication year - 2005
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl023183
Subject(s) - coral , aragonite , deglaciation , geology , interglacial , oceanography , glacial period , quaternary , porites , paleontology , calcite
The Sr/Ca of coral skeletons demonstrates potential as an indicator of sea surface temperatures (SSTs). However, the glacial‐interglacial SST ranges predicted from Sr/Ca of fossil corals are usually higher than from other marine proxies. We observed infilling of secondary aragonite, characterised by high Sr/Ca ratios, along intraskeletal pores of a fossil coral from Papua New Guinea that grew during the penultimate deglaciation (130 ± 2 ka). Selective microanalysis of unaltered areas of the fossil coral indicates that SSTs at ∼130 ka were ≤1°C cooler than at present in contrast with bulk measurements (combining infilled and unaltered areas) which indicate a difference of 6–7°C. The analysis of unaltered areas of fossil skeletons by microprobe techniques may offer a route to more accurate reconstruction of past SSTs.