|Título||Sediment fluxes along the northeastern European Margin: inferring hydrological changes between 20 and 8 kyr|
|Publication Type||Journal Article|
|Authors||Abrantes, F, Baas, J, Haflidason, H, Rasmussen, T, Klitgaard, D, Loncaric, N, Gaspar, L|
|Year of Publication||1998|
|Pagination||7 - 23|
|Palavras-chave||eastern North Atlantic; palaeocirculation; sedimentary fluxes; Heinrich event 1; productivity|
In an attempt to delineate past hydrographic conditions on the northeastern Atlantic Ocean Margin along a latitudinal transect (37°–63°N) and link the eastern North Atlantic Ocean with the Norwegian Sea, we have investigated planktonic and benthic stable oxygen isotopes, as well as abundances and fluxes of planktonic and benthic foraminifera, calcium carbonate, organic carbon, and detrital grains in six sediment cores studied by the ENAM project. In our joint approach, we focused on the major climatic events of the last 20 kyr, that is, the Last Glacial Maximum (LGM), the Heinrich event 1 (H1), the Younger Dryas (YD) and the Holocene Climatic Optimum (HCO). SIMMAX temperature estimates suggest glacial SSTs off Portugal, similar to Holocene values, contradicting the proposed polar front position of CLIMAP Project Members (1976). Besides, increased planktonic and benthic foraminiferal fluxes in the Norwegian Sea and the Faeroe Islands cores point to Nordic Seas partially ice-free with seasonally productive polynas. Multiple IRD spikes observed at the Faeroe Islands and Norwegian Sea sites, coeval with H1, suggest multiple pulses of the Fenno-Scandian ice sheet. At the same time the presence of IRD on the Portuguese Margin cores confirms the southward influence of icebergs. The increase in foraminiferal abundances and fluxes that parallel IRD spikes at all sites suggests that times of increased productivity either succeed or occur simultaneously with the iceberg surges in the open North Atlantic. Productivity conditions similar to those observed during H1 are also registered during the YD even though planktonic foraminiferal assemblages suggest less cold conditions.
|Short Title||Marine Geology|