Periglaciation suggests an environment located on the margin of past glaciers. It has also been attributed to a climate with a tundra-like vegetation with a permanently frozen
subsoil. Usually, the term is taken in the latter sense, but periglacial is used in the former definition when discussing periglacial lakes. Freeze and thaw cycles influence landscapes outside areas of past glaciation. Therefore, periglacial environments are anywhere that freezing and thawing modify the landscape in a significant manner. The tundra climate or periglacial zone is just outside of glaciated areas. The processes of
erosion in these glacial-peripheral zones are markedly different than present processes, therefore their effects have been noted. Chief actions in these zones include
solifluction and
frost-shattering processes, the effects of which can be seen in the south of the
Bristol Channel. == Occurrence of Periglacial Lakes through Geologic Time ==