Magnetic characterisation and correlation of a Younger Dryas tephra in North Atlantic marine sediments

A technique for identifying non-visible basaltic tephra-rich horizons of Younger Dryas (YD)/Greenlancl Stadial (GS) 1 age in northeast Atlantic sediments using rapid, non-destructive magnetic measurements is presented. Three high-resolution marine sediment cores have been studied in all E W transect...

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Bibliographic Details
Published in:Journal of Quaternary Science
Main Authors: Peters, Clare, Austin, William Edward Newns, Walden, John, Hibbert, Fiona D.
Format: Article in Journal/Newspaper
Language:English
Published: 2010
Subjects:
tephra
marine sediments
magnetic measurements
Younger Dryas
geochemistry
GLACIAL-INTERGLACIAL TRANSITION
VEDDE ASH LAYER
NGRIP ICE CORE
VOLCANIC ASH
HIGH-RESOLUTION
LATE QUATERNARY
WESTERN NORWAY
NORWEGIAN SEA
YR BP
ICELAND
Barra
Norway
Norwegian Sea
Rockall Trough
ice core
Iceland
NGRIP
North Atlantic
Northeast Atlantic
Online Access:https://research-portal.st-andrews.ac.uk/en/researchoutput/magnetic-characterisation-and-correlation-of-a-younger-dryas-tephra-in-north-atlantic-marine-sediments(5b6628f3-bac9-412d-a58d-050133d0f268).html
https://doi.org/10.1002/jqs.1320
http://www.scopus.com/inward/record.url?scp=77449141101&partnerID=8YFLogxK
Description
Summary:A technique for identifying non-visible basaltic tephra-rich horizons of Younger Dryas (YD)/Greenlancl Stadial (GS) 1 age in northeast Atlantic sediments using rapid, non-destructive magnetic measurements is presented. Three high-resolution marine sediment cores have been studied in all E W transect across the Hebridean margin: St Kilda Basin (MD95-2007), Barra Fan (MD95-2006) and Rockall Trough (MD04-2822). Magnetic susceptibilities and remanent magnetisations were measured at contiguous 1 cm resolution on bulk sediments. In all three cores, an interval with higher proportions of hard magnetic minerals coincides with a clearly defined peak in basaltic tephra shard (>250 mu m) counts, which can be constrained to the early part of the YD/GS1 based on faunal climate proxies. Electron microprobe analyses of the magnetically distinct basaltic tephra interval, in all three cores, displays the same major element geochemistry as published for the Vedde basaltic (I Tab. 1), i.e. sourced from the Icelandic volcano Kat la. The identification of transitional alkalic basaltic tephras within marine sediments could potentially be facilitated by magnetic analysis as a useful chronostratigraphic screening tool. Copyright (C) 2009 John Wiley & Sons, Ltd.

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