The last British Ice Sheet: A review of the evidence utilised in the ...

palaeo-surging has been reported from the area covered by the British Ice Sheet. Only future systematic,
regional assessments of sediment-landform associations can facilitate comparisons with contemporary
surging glacier landsystems (Evans and Rea, 1999, 2003; Evans et al., 1999) and therefore verify or refute
palaeo-surging activity.
3.6. Ice sheet dynamics and amphi-Atlantic climatic events
Considerable advances have been made in recent years with respect to the correlation of millennial scale
events around the margins of the North Atlantic, specifically in the identification of Dansgaard- Oeschger
events and Bond Cycles in the Greenland ice cores (e.g. Johnsen et al., 1992; Bond et al., 1993; Dansgaard et
al., 1993) and the massive calving episodes that affected the margins of the Laurentide and European ice
sheets, which launched iceberg armadas into the neighbouring oceans and deposited the Heinrich layers (e.g.
Heinrich, 1988; Bond and Lotti, 1995) that are now equated with short pulses of rapid cooling. Although
these amphi-Atlantic events have been identified in the unusually long palaeoecological records at locations
such as Gransmoor in East Yorkshire, Llanilid in south Wales, Whitrig Bog in southern Scotland and
Borrobol in northern Scotland (Mayle et al., 1999), evidence of British Ice Sheet responses to the events is
largely circumstantial (McCabe et al., 1998) and major moraine systems that could date to the same period
covered by the Bond Cycles and Heinrich events remain largely undated (cf. Wester Ross moraine of ca.13
ka BP; Ballantyne et al., 1987; Ballantyne, 1993). Recent advances in cosmogenic isotope dating have
allowed Everest (2002) to date valley moraines in the Cairngorms to 15–15.8 ka. This approach clearly needs
to be extended to the major moraine systems of Britain in order to date ice sheet dynamics more precisely and
allow comparisons with the high resolution palaeoclimate record available in the Greenland ice core
stratigraphy.
4. Conclusion
This paper has reviewed the nature of the glacial geomorphological evidence for the last British Ice Sheet in
Scotland, England, Wales, the Isle of Man and surrounding continental shelves. It is based upon the
published literature and unpublished PhD theses and is compiled on a Glacial Map of Britain (Clark et al.,
2004). The map also contains further information captured from unpublished BGS drift sheets not
accompanied by memoirs, which are not reviewed here but are listed in the GIS data base. Although the Irish
sector of the ice sheet has been excluded in this study, future work will concentrate on compiling a similar
map for Ireland. The mapping and interpretation of glacial landforms reported here and depicted in the
Glacial Map of Britain is patchy in coverage, nonsystematic in approach and spans more than 100 years of
field research. As a result Britain presently has no comprehensive map of glacial landforms and this study has
highlighted the extent of the shortfall so that future research can target critical regions and work towards the
compilation of a glacial map that compares with those of other countries. Of priority for future glacial
56