Late Quaternary foraminiferal record in Murchisonfjorden, Nordaustlandet, Svalbard
Benthic foraminiferal assemblages from Nordaustlandet, Svalbard, are described for the first time with the objective of reconstructing the palaeoenvironmental conditions in the area during the late Quaternary. Investigations were carried out on marine deposits exposed along the southern shores of Murchisonfjorden. Five foraminiferal assemblages (A1–A5), representing different palaeoenvironmental conditions, were identified from the marine intervals, i.e., the Cassidulina reniforme–Elphidium albiumbilicatum assemblage (A1) from the Early Weichselian, the Islandiella helenae–Cibicides lobatulus assemblage (A2) from the Early Weichselian, the Cibicides lobatulus–Cassidulina reniforme assemblage (A3) from marine isotope stage 3, the Elphidium albiumbilicatum assemblage (A4) from the early Holocene and the Astrononion gallowayi assemblage (A5) from the mid-Holocene. Assemblages A1–A5 are compared with modern and fossil Quaternary assemblages from Arctic regions. Particularly notable is the fact that a well-defined Middle Weichselian assemblage in Svalbard is described for the first time, i.e., the Cibicides lobatulus–Cassidulina reniforme assemblage. All the assemblages from Nordaustlandet represent glacier-distal, inner-shelf environments with an open connection to the ocean. The results reveal the occurrence of three marine intervals (ice-free periods) in the north-western part of Nordaustlandet during the Weichselian, as well as ice-free conditions during most of the Holocene. A comparison of the assemblages from Nordaustlandet with previously published foraminiferal zones from onshore sections elsewhere in Svalbard show some degree of similarity, but also show considerable variation in species compositions, presumably caused by local environmental differences.
Document Type: Research Article
Department of Earth Sciences, Aarhus University, Høegh-Guldbergs Gade 2, DK-8000 Århus C, Denmark
Department of Geosciences and Geography, Division of Geology, University of Helsinki, Gustaf Hällströmin katu 2a, PO Box 64, FI-00014 Helsinki, Finland
Publication date: December 1, 2010