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Miocene deep-water agglutinated foraminifera from the Lomonosov Ridge and the opening of the Fram Strait

Domenii publicaţii > Ştiinţele pământului şi planetare + Tipuri publicaţii > Articol în revistã ştiinţificã

Autori: Kaminski, M.A., Silye, L.,& Kender, S.

Editorial: Micropaleontology, 55(2-3), p.117-135, 2009.

Rezumat:

Deep-water agglutinated Foraminifera (DWAF) were recovered from Miocene to Pliocene sediments in 103 samples
from IODP Hole M0002A on the Lomonosov Ridge. The First Occurrence of DWAF in Hole M0002A is observed just above the color
change corresponding to the boundary between Lithological Subunits 1/4 and 1/5 in Core section –44X-1. The foraminiferal record of
Hole M0002A consists entirely of agglutinated benthic species, largely sparse assemblages containing Cyclammina pusilla and
Alveolophragmium polarensis. The faunal succession in Hole M0002A is subdivided into three assemblages based on the stratigraphic
ranges of characteristic taxa: (1) a relatively diverse assemblage at the base of Lithological Subunit 1/4 (Cores 44X-1 to –38X), with
abundant agglutinated foraminifera including Reticulophragmium pusillum and Ammolagena clavata, indicating connections with the
North Atlantic. This assemblage displays the best preservation, which is here attributed to higher concentrations of dissolved silica in
pore waters (2) A less diverse assemblage characterized by Alveolophragmium polarensis with Adercotryma agterbergi, in the lower
part of Lithological Subunit 1/3 (Cores –38X to –35X); (3) a sparse residual assemblage within Lithological Subunit 1/3 with
Rhabdammina spp., A. polarensis and R. pusillum indicating poor preservation of organically-cemented DWAF in Cores –34X to
–10X.
A comparison of the DWAF assemblages from the Lomonosov Ridge with previously studied Miocene assemblages from ODP
Hole 909C in the Fram Strait, Norwegian-Greenland Sea (Kaminski et al. 2005), suggests that the inflow of Atlantic intermediate water
into the Arctic Ocean began prior to 17.5 Ma.

Cuvinte cheie: agglutinated foraminifera, Miocene, paleoceanography, Arctic

URL: http://www.micropress.org/micro_journal.html