The Archaeology of Britain: An introduction from ... - waughfamily.ca

The Lateglacial colonization of Britain
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THE END OF THE LAST GLACIATION
Younger Dryas
A return to much colder conditions in the period 10,800 to 10,000 BP is marked by a dramatic
fall of 5–7°C in mean annual sea temperatures in the North Atlantic. Further evidence of climatic
deterioration is indicated by the southern limit of winter sea ice which migrated from a position
close to Iceland (near where it is today) to a point off the north coast of Iberia. This, coupled
with potentially stronger cyclonic activity in the North Atlantic and a northerly wind flow, appears
to have provided the right conditions for increased precipitation, much of it probably in the form
of snow, feeding local glaciers in the Scottish Highlands and north Wales. According to the
GISP-2 ice-core data, the sharp fall in temperatures and the return to a more glacial climate seem
to have occurred extremely rapidly, perhaps within as little as a few centuries (Alley et al. 1993).
These climatic changes are reflected in the pollen record by evidence for the disruption of
birch parkland and increased frequencies of plant communities typical of open tundra. A similar
climatic signal is given by the fossil beetle faunas which show that, if anything, temperatures in
Britain were slightly cooler than those of western Europe. The latter observation is consistent
with the deflection of the warm Gulf Stream currents away from the western European seaboard.
The return to more open tundra-like conditions is also indicated by the reappearance of reindeer,
as well as several records of steppe pika (Ochotona pusilla). The possibility that the climate became
progressively more arid in the later part of the Younger Dryas is implied by the occurrence of
several different species of Artemisia. Such dryness may also have stimulated the growth of wild
grasses, creating grazing conditions especially favourable to wild horses and reindeer. Certainly,
the few radiocarbon dates on horses of this period all belong to the second half of the stadial.
Human settlement and the question of continuity of occupation
Recent reviews have drawn attention to the very limited evidence of human activities in the
Younger Dryas (Barton in Barton et al. 1991; Cook and Jacobi 1994). In fact, there are only three
reliable AMS radiocarbon dates that, at two standard deviations, fall wholly within this period.
Potentially the most interesting of these comes from a cache of deer bones with cut-marks at
Elderbush Cave (Staffordshire) which can be dated to 10,600±110 BP. This date falls close to the
thermal minimum of the stadial and, if correctly interpreted, implies that human settlement was
not inhibited by even the most extreme cold conditions. Some doubts have been expressed about
the Elderbush date, however, because of the uncertain conservation history of the bones used to
obtain it.
Much greater confidence can be attributed to two dates from after the period of maximum
cold during the stadial (c.10,500 BP). The first comes from a worked reindeer antler object, which
has been compared to a ‘Lyngby axe’, found at Earl’s Barton (Northamptonshire). This has been
directly dated to 10,320±150 BP. The other is for the older of two dates on wild horse from
scatter ‘A’ at Three Ways Wharf, Uxbridge (Greater London), with an age of 10,270±100 BP. The
latter is particularly significant because it is associated with a lithic assemblage.
The lithic artefacts from Three Ways Wharf scatter ‘A’ (Lewis in Barton et al. 1991) include
long blades (12 cm or more in maximum length) and a small number of obliquely truncated
microliths with basal retouch (Figure 2.9). There can be no doubt about this association, because
one of the microliths can be refitted to a long blade core. Amongst the collection, one blade
displays heavy battering on its margins. Such edge bruising may have been caused by chopping
through antler or by replenishing sandstone hammers, and this artefact is identical to those termed
lames machurées (Barton 1989).