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Rashid, H; Hesse, R; Piper, Djw. |
An additional Heinrich ice-rafting event is identified between Heinrich events 5 and 6 in eight cores from the Labrador Sea and the northwest Atlantic Ocean. It is characterized by sediment rich in detrital carbonate (40% CaCO3) with high concentration of floating dropstones, high coarse-fraction (% > 150 mum) content, and has a sharp contact with the underlying but grades into the overlying hemipelagic sediment. It also shows lighter delta(18)O(Npl) values, indicating freshening due to iceberg rafting and/or meltwater discharge. This event is correlated with Dansgaard-Oeschger event 14 and interpreted as an additional Heinrich event, H5a. The thickness of H5a in the Labrador Sea reaches up to 220 cm. This additional Heinrich event has also been... |
Tipo: Text |
Palavras-chave: Heinrich events; Nepheloid flow deposits; GISP2; Dansgaard-Oeschger cycle; Labrador Sea. |
Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00225/33658/32098.pdf |
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Aubouin, J; Van Huene, R; Azema, J; Blackinton, G; Carter, Ja; Coulbourn, W T; Cowan, D S; Curiale, Ja; Dengo, Ca; Faas, Rw; Harrison, W; Hesse, R; Hussong, Dm; Ladd, Jw; Muzylev, N; Shiki, T; Thompson, Pr; Westberg, J. |
The Middle America Trench off Guatemala was transected by 24-channel seismic-reflection surveys, seismic-refraction surveys, and drilling with the Glomar Challanger . The drilling was doneat three sites on the oceanic Cocos plate and four sites on the Caribbean plate. These plates converge at about 10 cm/yr as indicated by global plate reconstruction. On the oceanic Cocos plate a basal chalk sequence of lower and middle Miocene age is overlain by a thin interval of abyssal clay. In contrast is the Cretaceous to lower Miocene claystone sequence recovered only at a site 3 km landward of the trench axis where drilling penetrated the hemipelagic slope deposits. A large amount of sediment along with ocean crust has been subducted during the present (Miocene to... |
Tipo: Text |
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Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/00245/35671/34179.pdf |
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