Britain's periglacial legacy and glacigenic sediments

What effects did permafrost have on the near-surface geology in Britain? Areas of Britain were affected by periglacial processes throughout various Quaternary cold stages. In many instances, periglacial processes acted to breakdown and weaken near-surface materials and also in places remobilise them. Understanding periglacial processes, and the distribution of near-surface material affected by them, has major implications on phenomena such as ground stability, soil management, landsliding, aquifer recharge and vulnerability.

Currently, research is being in two areas of East Anglia. Firstly, on the north Norfolk coast, research is being undertaken with scientists from the University of Keele and the University of Sussex to examine the role of ancient permafrost within the subglacial deformation and the detachment of glaciotectonic rafts. Secondly, in the Brecks adjacent to the Fen Basin, studies are being undertaken in collaboration with the University of Sheffield into the distribution, origins and age of the 'coversand'. The 'coversand' is largely an aeolian sand laid down and subsequently reworked during various cold climates events within the Late Pleistocene and Holocene.

Detailed examination of the trace element geochemistry of soils developed on coversand within the Brecks has demonstrated these soils to be rich in hafnium (Hf) and zirconium (Zr). This has enabled a residual coversand layer to be mapped extensively across other areas of East Anglia.

Applied characteristics of glacigenic sequences

Landslide at Sidetrand

Almost two-thirds of Britain is covered by a veneer of glacigenic sediment of variable thickness. In most cases, these sediments do not form simple layer-cake sequences but are both sedimentologically and structurally complex. This has major implications for the geotechnical, engineering and hydrogeological properties of these sequences. Research into the sedimentology and structure of glacigenic sequences by BGS scientists will greatly enhance our knowledge of the applied aspects of glacial sequences. Currently, members of the team are examining the role of glaciotectonic structures in controlling the distribution and style of landslides along the north Norfolk coast.

Contact

Contact Dr Jonathan Lee or Dr Emrys Phillips for further information.