British Ice Sheet dynamics inferred from North Atlantic ice‐rafted debris records spanning the last 175 000 years

Hibbert, Fiona D.; Austin, William E. N.; Leng, Melanie J.; Gatliff, Robert

doi:10.1002/jqs.1331

Cited by 73 publications

(86 citation statements)

References 157 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Bradwell et al, 2008;van Landeghem et al, 2008;Ó Cofaigh et al, 2010a) and a series of marine sediment cores sampled from shelf and abyssal environments (e.g. Knutz et al, 2001;Peck et al, 2007;Hibbert et al, 2009). Though the mapping of glacial bedforms cannot be used to formally define glacial limits, they do provide information on ice sheet evolution, particularly changes in the mass centres, ice divides and flow geometry of different sectors (e.g.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Extent and timing of the Last Glacial Maximum (LGM) in Britain and Ireland: a review

Chiverrell

Thomas

2010

J Quaternary Science

View full text Add to dashboard Cite

The Last Glacial Maximum (LGM) of Marine Isotope Stage (MIS) 2 is defined here as the period either of maximum global ice volume or in which major ice sheets reached their maximum extent. Both definitions lack clarity as there is no reason to suppose that maximum volumes or limits were reached simultaneously at either all ice sheets or around the margins of individual ice sheets. Here we review the traditional terrestrial limits of the BIIS (British-Irish Ice Sheet), examine developments in understanding the offshore record, and attempt a redefinition of the extent and timing of the MIS 2 maximum. As a working chronological model the build-up of the BIIS is assigned to after 35-32 ka, the maximum to the period 27-21 ka and a more limited readvance after 19 ka. As marginal oscillations, driven by ice sheet dynamics, appear to have characterised much of the advance, and especially the retreat of the BIIS, caution should be exercised in assigning climatic significance to the many identified ice limits or still-stands. While much of the terrestrial limit in Britain remains relatively unaltered, significant revision is required offshore around Britain and Ireland, to portray an extensive ice advance to the shelf edge and a period when the BIIS was conjoined with the adjacent Fenno-Scandinavian Ice Sheet. Although there appears to be a broad synchrony between the BIIS and other major ice sheets, local controls have produced some variation in the timing of advance to and retreat from maximum limits for particular ice streams or lobes, but much of the offshore limit remains very poorly age constrained. Consequently, a key objective in future research should be to improve and refine the chronological control for all portions of the maximum margin of the BIIS and its subsequent retreat stages.

show abstract

Section: Introductionmentioning

confidence: 99%

“…Marine fans fronting the northeast Atlantic continental shelf and the sediment record from less proximal settings have contributed evidence for ice raft debris sourced from the shelving margins of a BIIS (e.g. Hibbert et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Extent and timing of the Last Glacial Maximum (LGM) in Britain and Ireland: a review

Chiverrell

Thomas

2010

J Quaternary Science

View full text Add to dashboard Cite

show abstract

“…The YD/GS1, defined by high relative abundance of the polar planktonic foraminifer Neogloboquadrina pachyderma (sinistral) (Np(s)) , spans an interval of over 1 m. MD04-2822 (568 50.54 0 N, 118 22.96 0 W) is a 37.7 m giant piston core taken from a water depth of 2344 m from the Rockall Trough. The core extends back to MIS6 (Hibbert et al, 2009). The YD/GS1, defined by Np(s) (Hibbert et al, 2009), spans an interval of approximately 50 cm.…”

Section: Core Materialsmentioning

confidence: 99%

“…The core extends back to MIS6 (Hibbert et al, 2009). The YD/GS1, defined by Np(s) (Hibbert et al, 2009), spans an interval of approximately 50 cm.…”

Section: Core Materialsmentioning

confidence: 99%

See 1 more Smart Citation

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

Peters

Austin

Walden

et al. 2009

J Quaternary Science

Self Cite

View full text Add to dashboard Cite

A technique for identifying non-visible basaltic tephra-rich horizons of Younger Dryas (YD)/Greenland 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 an 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 mm) 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 Katla. The identification of transitional alkalic basaltic tephras within marine sediments could potentially be facilitated by magnetic analysis as a useful chronostratigraphic screening tool.

show abstract

Magnetic unmixing of first‐order reversal curve diagrams using principal component analysis

Lascu

Harrison

et al. 2015

Geochem Geophys Geosyst

View full text Add to dashboard Cite

We describe a quantitative magnetic unmixing method based on principal component analysis (PCA) of first-order reversal curve (FORC) diagrams. For PCA, we resample FORC distributions on grids that capture diagnostic signatures of single-domain (SD), pseudosingle-domain (PSD), and multidomain (MD) magnetite, as well as of minerals such as hematite. Individual FORC diagrams are recast as linear combinations of end-member (EM) FORC diagrams, located at user-defined positions in PCA space. The EM selection is guided by constraints derived from physical modeling and imposed by data scatter. We investigate temporal variations of two EMs in bulk North Atlantic sediment cores collected from the Rockall Trough and the Iberian Continental Margin. Sediments from each site contain a mixture of magnetosomes and granulometrically distinct detrital magnetite. We also quantify the spatial variation of three EM components (a coarse silt-sized MD component, a fine silt-sized PSD component, and a mixed clay-sized component containing both SD magnetite and hematite) in surficial sediments along the flow path of the North Atlantic Deep Water (NADW). These samples were separated into granulometric fractions, which helped constrain EM definition. PCA-based unmixing reveals systematic variations in EM relative abundance as a function of distance along NADW flow. Finally, we apply PCA to the combined data set of Rockall Trough and NADW sediments, which can be recast as a four-EM mixture, providing enhanced discrimination between components. Our method forms the foundation of a general solution to the problem of unmixing multicomponent magnetic mixtures, a fundamental task of rock magnetic studies.

show abstract

British Ice Sheet dynamics inferred from North Atlantic ice‐rafted debris records spanning the last 175 000 years

Cited by 73 publications

References 157 publications

Extent and timing of the Last Glacial Maximum (LGM) in Britain and Ireland: a review

Extent and timing of the Last Glacial Maximum (LGM) in Britain and Ireland: a review

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

Magnetic unmixing of first‐order reversal curve diagrams using principal component analysis

Contact Info

Product

Resources

About