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| Channell, J. E. T.; Harrison, R. J.; Lascu, I.; Mccave, I. N.; Hibbert, F. D.; Austin, W. E. N.. |
| Core MD04-2822 from the Rockall Trough has apparent sedimentation rates of ∼ 1 m/kyr during the last deglaciation (Termination I). Component magnetization directions indicate a magnetic excursion at 16.3 m depth in the core, corresponding to an age of 26.5 ka, implying an excursion duration of ∼350 years. Across Termination I, the mean grain size of sortable silt implies reduced bottom-current velocity in the Younger Dryas and Heinrich Stadial (HS)-1A, and increased velocities during the Bølling-Allerød warm period. Standard bulk magnetic parameters imply fining of magnetic grain size from the mid-Younger Dryas (∼12 ka) until ∼ 8 ka. First-order reversal curves (FORCs) were analyzed using ridge extraction to differentiate single domain (SD) from background... |
| Tipo: Text |
Palavras-chave: Magnetic granulometry; FORC-PCA analysis; Sortable silt; Magnetic excursion; Termination I; Rockall Trough. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00333/44456/44128.pdf |
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| Skinner, Lc; Shackleton, Nj. |
| A sequence of accelerator mass spectrometry (AMS) C-14 dates performed on benthic and planktonic foraminifera from a northeast Atlantic deep-sea core (MD99-2334K; 37degrees480N, 10degrees10'W; 3146 m) permit the reconstruction of deep water ,,C-14 ventilation ages'' across the last deglaciation. The records from MD99-2334K have been placed on the GISP2 timescale via the synchrony of temperature changes recorded in the Greenland ice cores and in North Atlantic planktonic delta(18)O(cc) (calcite delta(18)O). On the basis of a range of estimates for past source water Delta(14)C, this permits the estimation of C-14 projection ventilation ages for comparison with benthic-planktonic C-14 age differences. Although the accurate estimation of past ventilation ages... |
| Tipo: Text |
Palavras-chave: Termination I; Ventilation age; Thermohaline circulation. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00228/33971/32339.pdf |
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