Benthic foraminifera of late Quaternary sediments in the northern North Atlantic

• Main Author: Nees, Stefan
• Format: Other/Unknown Material
• Language: English
• Published: PANGAEA 1993
• Subjects: Arctic Ocean; ARK-VII/1; GIK21906-2 PS17/081; GIK23068-3; GIK23256-1; GIK23414-9; Global Environmental Change: The Northern North Atlantic; Greenland Sea; KAL; Kasten corer; KOL; M17/2; M2/2; M23414; M7/2; Meteor (1986); Northeast Atlantic; Norwegian Sea; Piston corer (Kiel type); Polarstern; PS17; PS1906-2; SFB313; Foraminifera*; Greenland; North Atlantic
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.704509; https://doi.org/10.1594/PANGAEA.704509

Four long sediment cores from locations in the Framstrait, the Norwegian-Greenland Seas and the northern North Atlantic were analysed in a high resolution sampling mode (1 - 2 cm density) for their benthic foraminiferal content. In particular the impact of the intense climatic changes at glacial/interglacial transitions (terminations I and II) on the benthic community have been of special interest. The faunal data were investigated by means of multivariate analysis and represented in their chronological occurence. The most prominent species of benthic foraminifera in the Norwegian-Greenland Seas are Oridorsalis umbonatus, Cibicidoides wuellerstorfi, the group of Cassidulina, Pyrgo rotalaria, Globocassidulina subglobosa and fragmented tubes of arenaceous species. The climatic signal of termination I as well as termination II is recorded in the fossil foraminiferal tests as divided transition from glacial to interglacial. The elder INDAR maximum (individuals accumulation rate = individuals/sq cm * 1.000 y; Norwegian-Greenland Seas: average 3.000 - 6.000 individuals/sq cm * 1.000 y; northern North Atlantic: average 150 individuals/sq cm * 1.000 y) is followed by a period of decreased values. The second, younger maximum reaches comparable values as the elder maximum. The interglacial INDAR are in average 700 individuals/sq cm * 1.000 y in the Norwegian-Greenland Seas and 200 individuals/sq cm * 1.000 y in average in the northern North Atlantic. The occurence of the elder INDAR maximum shows a distinct chronological transgressivity between the northern North Atlantic (12.400 ybp.) and the Framstrait (8.900 ybp.). The time shift from south to north amounts 3.500 yrs., the average expanding velocity 0,78 km per year. Within the Norwegian-Greenland Seas the average expanding velocity amounts 0,48 km per year. This chronological transgressivity is interpreted as impact of the progressive expanding of the North Atlantic and the Norwegian Current during the deglaciation. The dynamic of the faunal development is defined as ...