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Mortyn, Pg; Charles, Cd; Ninnemann, Us; Ludwig, K; Hodell, Da. |
Many applications of the Vostok ice core depend critically on the ability to make stratigraphic ties to marine records in the adjacent Southern Ocean. Here we present oxygen isotopic records from high accumulation rate sites in the South Atlantic sector of the Southern Ocean, collected for the purpose of complementing the recently extended deltaD record from the Vostok ice core. The combination of several planktonic foraminiferal delta(18)O records from northern subantarctic piston cores demonstrates that all of the millennial-scale oscillations expressed in the Vostok ice core over the last 60 ky are also present in marine records. The observations also support the assumption that the millennial-scale oscillations common to both marine and ice archives... |
Tipo: Text |
Palavras-chave: Paleoclimatology; Paleoceanography; Meteorology and atmospheric dynamics : paleoclimatology. |
Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00226/33707/32126.pdf |
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Koc, N; Labeyrie, L; Manthe, S; Flower, Bp; Hodell, Da; Aksu, A. |
Well-preserved diatoms are present in high sedimentation rate Pleistocene cores retrieved on ocean Drilling Program (ODP) Legs 151, 152, 162 and IMAGES cruises of RN Marion Dufresne from the North Atlantic. Investigation of the stratigraphic occurrence of diatom species shows that the youngest diatom event observed in the area is the last occurrence (LO) of Proboscia curvirostris (Jouse) Jordan and Priddle. P. curvirostris is a robust species that can easily be identified in the sediments, and therefore can be a practical biostratigraphic tool. We have mapped its: areal distribution, and found that it stretches from 40 degreesN to 80 degreesN in the North Atlantic. Further, we have correlated the LO P. curvirostris to the oxygen isotope records of six... |
Tipo: Text |
Palavras-chave: Biostratigraphy; North Atlantic; Diatoms; Pleistocene; Paleoceanography; Isotope stratigraphy; Oxygen. |
Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/00221/33210/31708.pdf |
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Sierro, Fj; Hodell, Da; Curtis, Jh; Flores, Ja; Reguera, I; Colmenero-hidalgo, E; Barcena, Ma; Grimalt, Jo; Cacho, I; Frigola, J; Canals, M. |
Down-core samples of planktonic and benthic foraminifera were analyzed for oxygen and carbon isotopes in International Marine Past Global Changes Study (IMAGES) core MD99-2343 in order to study the interactions between climate change in the Northern Hemisphere and the western Mediterranean thermohaline circulation at times of Heinrich events (HE). Our results confirm the antiphase correlation between enhanced North Atlantic Deep Water formation and low ventilation in the Mediterranean. However, this study reveals that this antiphase relationship in deepwater formation between the North Atlantic and Mediterranean was interrupted during times of HE when the injection of large volumes of water from melting icebergs reached the entrance to the Mediterranean.... |
Tipo: Text |
Palavras-chave: Climatic change; Heinrich events; Mediterranean Sea; Carbon and oxygen isotopes; Thermohaline circulation; Pleistocene. |
Ano: 2005 |
URL: https://archimer.ifremer.fr/doc/00232/34354/32759.pdf |
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