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T8
The Evolution of Periglacial Patterned Ground In East Anglia
Stephen Hitchen 1 , Mark D. Bateman 1 *, Julian B. Murton 2 , Jonathan R. Lee 3 , and Philip L.
Gibbard 4
1 Geography Department, Sheffield University, Winter St., Sheffield S10 2TN
2 Department of Geography, University of Sussex, Falmer, East Sussex BN1 9RH
3 British Geological Survey, Keyworth, Nottingham NG12 5GG
4 Department of Geography, University of Cambridge, Downing Place, Cambridge CB2 3EN
During the Late Pleistocene, East Anglia in Britain experienced multiple cycles of
periglacial activity. This research investigates whether the extensive well-developed
chalkland patterned ground in this region was formed or reworked during one or more of
these cycles or whether it reflects conditions during the Dimlington and/or Younger Dryas
Stadials which were the last periods of intensive periglacial activity to affect lowland
Britain. Using twenty-six coversand samples from six spatially diverse polygon and stripe
sites, single grain optically stimulated luminescence (OSL) measurements have been
used to differentiate post-depositional disturbance from sand deposited under periglacial
conditions. Cluster analysis of this OSL data has been used to establish dominant ages of
periglacial sand burial. These have been used to reconstruct re-activation histories of the
periglacial phenomena thereby giving a better understanding of the timing and
development of periglacial conditions in East Anglia. Results show multiple phases of
activity within the last 90 -10 ka but nothing from earlier cold cycles. East Anglian
polygons and stripes appeared to have been most active in four phases; (1) ~55-60 ka, (2)
~31-35 ka, (3) ~20-22 ka and (4) ~11-12 ka. Most sites showed some activity around the
Greenland Stadial 2a and the Younger Dryas Stadial but polygon sites showed a longer
and more temporally and spatially varied record than those found at stripe sites.
Interpreted phases of activity mostly coincide with stadials within the last glacialinterglacial
cycle, possibly at the end of climatic cold phases.
Keywords: stripes; polygons; coversand; luminescence dating.