Change search
ReferencesLink to record
Permanent link

Direct link
Biogenic and detrital rich intervals in central arctic ocean cores identified using x ray fluorescence scanning
Stockholm University, Faculty of Science, Department of Geological Sciences.
Stockholm University, Faculty of Science, Department of Geological Sciences.
2013 (English)In: Polar Research, ISSN 0800-0395, E-ISSN 1751-8369, Vol. 32, 18386- p.Article in journal (Refereed) Published
Abstract [en]

X-ray fluorescence (XRF) scanning of sediment cores from the Lomonosov Ridge and the Morris Jesup Rise reveals a distinct pattern of Ca intensity peaks through Marine Isotope Stages (MIS) 1 to 7. Downcore of MIS 7, the Ca signal is more irregular and near the detection limit. Virtually all major peaks in Ca coincide with a high abundance of calcareous microfossils; this is particularly conspicuous in the cores from the central Arctic Ocean. However, the recorded Ca signal is generally caused by a combination of biogenic and detrital carbonate, and in areas influenced by input from the Canadian Arctic, detrital carbonates may effectively mask the foraminiferal carbonates. Despite this, there is a strong correlation between XRF-detected Ca content and foraminiferal abundance. We propose that in the Arctic Ocean north of Greenland a common palaeoceanographic mechanism is controlling Ca-rich ice-rafted debris (IRD) and foraminiferal abundance. Previous studies have shown that glacial periods are characterized by foraminfer-barren sediments. This implies that the Ca-rich IRD intervals with abundant foraminifera were most likely deposited during interglacial periods when glaciers left in the Canadian Arctic Archipelago were still active and delivered a large amount of icebergs. At the same time, conditions were favourable for planktic foraminifera, resulting in a strong covariance between these proxies. Therefore, we suggest that the XRF scanner's capability to efficiently map Ca concentrations in sediment cores makes it possible to systematically examine large numbers of cores from different regions to investigate the palaeoceanographic reasons for the calcareous microfossils' spatial and temporal variability.

Place, publisher, year, edition, pages
2013. Vol. 32, 18386- p.
Keyword [en]
Foraminifera, Arctic Ocean, IRD, calcareous microfossils, XRF scanning
National Category
Oceanography, Hydrology, Water Resources Ecology
URN: urn:nbn:se:su:diva-88337DOI: 10.3402/polar.v32i0.18386ISI: 000314828200001OAI: diva2:611768


Available from: 2013-03-18 Created: 2013-03-12 Last updated: 2014-03-28Bibliographically approved
In thesis
1. Late Quaternary Biostratigraphy and Paleoceanography of the central Arctic Ocean
Open this publication in new window or tab >>Late Quaternary Biostratigraphy and Paleoceanography of the central Arctic Ocean
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The central Arctic Ocean is one of the least explored deep sea regions and long biostratigraphic sediment records are sparse. The main focus of this thesis is the Arctic Ocean foraminiferal record and its application to reconstruct paleoceanographic variations and summer sea ice cover changes between late Quaternary interglacial periods. One of the studied cores was retrieved from the central Lomonosov Ridge Intra Basin. This core contains a relatively high-resolution biostratigraphic record spanning Marine Isotope Stages (MIS) 1–3, although with a hiatus encompassing the Last Glacial Maximum. Radiocarbon age calibrations in this core show a decreasing trend of high marine reservoir ages of about 1400 years during the last deglaciation to 700 years in the late Holocene. The cores from the Lomonosov Ridge off Greenland and the Morris Jesup Rise contain preserved calcareous microfossils further back in time than most previously studied central Arctic Ocean cores. The calcium content estimated by X-ray fluorescence scanning of these cores shows a distinct pattern of calcium rich intervals coinciding with peaks in foraminiferal abundance in the sediment record of MIS 1–7. The calcium peaks originate from material accumulated during interglacials, primarily through detrital carbonate and dolomite input from the decaying North American ice sheet and secondarily from biogenic material. Intervals of calcareous benthic foraminifera are found in pre MIS 7 sediments on both the southern Lomonosov Ridge and Morris Jesup Rise. Their assemblage composition and stable carbon isotope data suggest increased primary production and decreased summer sea ice cover compared to the Holocene central Arctic Ocean. This is also suggested for an interval of high abundance of the subpolar planktic foraminifera Turborotalita quinqueloba on the southern Lomonosov Ridge with a proposed MIS 11 age.

Place, publisher, year, edition, pages
Stockholm: Department of Geological Sciences, Stockholm University, 2011. 32 p.
Meddelanden från Stockholms universitets institution för geologiska vetenskaper, 345
Arctic Ocean, Quaternary, biostratigraphy, foraminifera, paleoceanography
National Category
Other Earth and Related Environmental Sciences
Research subject
Marine Geoscience
urn:nbn:se:su:diva-57245 (URN)978-91-7447-311-7 (ISBN)
Public defence
2011-06-10, Ahlmansalen, Geovetenskapens hus, Svante Arrhenius väg 12, Stockholm, 10:00 (English)

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 3: Submitted.

Available from: 2011-05-12 Created: 2011-05-04 Last updated: 2014-03-28Bibliographically approved

Open Access in DiVA

Fulltext(1537 kB)70 downloads
File information
File name FULLTEXT01.pdfFile size 1537 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Other links

Publisher's full text

Search in DiVA

By author/editor
Hanslik, DanielaJakobsson, Martin
By organisation
Department of Geological Sciences
In the same journal
Polar Research
Oceanography, Hydrology, Water ResourcesEcology

Search outside of DiVA

GoogleGoogle Scholar
Total: 70 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 50 hits
ReferencesLink to record
Permanent link

Direct link