Iberian Margin 420 kyr geochemical and color variations record ...
Here we report 420 kyr long records of sediment geochemical and color variations from the southwestern Iberian Margin. We synchronized the Iberian Margin sediment record to Antarctic ice cores and speleothem records on millennial time scales and investigated the phase responses relative to orbital f...
| Main Authors: | , , , , , , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
PANGAEA
2013
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.1594/pangaea.831762 https://doi.pangaea.de/10.1594/PANGAEA.831762 |
| Summary: | Here we report 420 kyr long records of sediment geochemical and color variations from the southwestern Iberian Margin. We synchronized the Iberian Margin sediment record to Antarctic ice cores and speleothem records on millennial time scales and investigated the phase responses relative to orbital forcing of multiple proxy records available from these cores. Iberian Margin sediments contain strong precession power. Sediment "redness" (a* and 570-560 nm) and the ratio of long-chain alcohols to n-alkanes (C26OH/(C26OH + C29)) are highly coherent and in-phase with precession. Redder layers and more oxidizing conditions (low alcohol ratio) occur near precession minima (summer insolation maxima). We suggest these proxies respond rapidly to low-latitude insolation forcing by wind-driven processes (e.g., dust transport, upwelling, precipitation). Most Iberian Margin sediment parameters lag obliquity maxima by 7-8 ka, indicating a consistent linear response to insolation forcing at obliquity frequencies driven ... : Supplement to: Hodell, David A; Crowhurst, Simon J; Skinner, Luke C; Tzedakis, Polychronis C; Margari, Vasiliki; Channell, James E T; Kamenov, George D; Maclachlan, Suzanne; Rothwell, Robin Guy (2013): Response of Iberian Margin sediments to orbital and suborbital forcing over the past 420 ka. Paleoceanography, 28(1), 185-199 ... |
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