Amphimelissa setosa (Cleve) (Polycystina, Nassellaria); a stratigraphic and paleoecological marker of migrating polar environments in the Northern Hemisphere during the Quaternary

Author(s): Bjorklund, Kjell R.; Hatakeda, Kentaro; Kruglikova, Svetlana B.; Matul, Alexander G.
Author Affiliation(s): Primary:
University of Oslo, Department of Geology, Oslo, Norway
Tohoku University, Japan
Russian Academy of Sciences, P. P. Shirshov Institute of Oceanology, Russian Federation
Volume Title: Stratigraphy
Source: Stratigraphy, 12(1), p.23-37. Publisher: Micropaleontology Press, New York, NY, United States. ISSN: 1547-139X
Note: In English. 60 refs.; illus., incl. strat. col., 2 plates, 3 tables, sketch map
Summary: Amphimelissa setosa is at present a species endemic to the Arctic province: the Arctic Ocean proper and its marginal seas. In the North Pacific Ocean and the Okhotsk Sea, its first occurrence was at 1.03 Ma and it became locally extinct at 72 ka. Its first recorded occurrence in the North Atlantic is at IODP Site U1314 at 414 ka in MIS 11, which is much older than previously documented by Matul and Abelmann (2005). This earlier first occurrence suggests that its migration from the North Pacific took place during MIS 11, with a higher sea-level stand than at present. The stratigraphic distribution of A. setosa shows seven peak occurrences: at 383.3 ka in MIS 11 (11.9%), 347.1 ka (64.6%) in MIS 10, at 319.2 ka (12.1%) in MIS 9,291.1 ka (16.4%)near base in MIS 8, at 74.4 ka (8.1%) in MIS 5a, at 53.7 ka (18.2%) in MIS 3, and at 21.1 ka (48.2%) in MIS 2, the two major peaks corresponding with glacial maxima. The prominent abundance peaks at MIS 10 and MIS 2 clearly reflect the southward penetration of the Arctic front. On the other hand, A. setosa is very rare or absent in the upper part of MIS 8 and during most of MIS 5. We suggest that during the upper part of MIS 8, A. setosa is not observed because of considerably lower biogenic silica. Its near absence during MIS 6 may be the result of relatively warmer oceanographic conditions in this glacial period without a significant southward migration of the polar front. Finally, morphometric analyses of A. setosa at the abundance peaks in MIS 10 and MIS 2 indicate that the specimens occurring in MIS 10 are somewhat, but significantly larger than those occurring in MIS 2 with also a slight difference in shape.
Year of Publication: 2015
Research Program: DSDP Deep Sea Drilling Project
IODP Integrated Ocean Drilling Program
IPOD International Phase of Ocean Drilling
ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Amphimelissa setosa; Atlantic Ocean; Cenozoic; DSDP Site 609; Deep Sea Drilling Project; Expedition 306; Expeditions 303/306; IODP Site U1314; IPOD; Integrated Ocean Drilling Program; Invertebrata; Labrador Sea; Leg 105; Leg 94; Lithostratigraphy; Marine environment; Microfossils; Mid-Atlantic Ridge; Morphology; Nassellina; North Atlantic; Northeast Atlantic; ODP Site 646; Ocean Drilling Program; Osculosida; Paleoclimatology; Paleoecology; Paleoenvironment; Pleistocene; Polycystina; Protista; Quaternary; Radiolaria; Statistical analysis
Coordinates: N495240 N495241 W0241417 W0241418
N581236 N581236 W0482206 W0482206
N562200 N562200 W0275300 W0275300
Record ID: 2016024641
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute.