The Mercia Mudstone Group in the UK is characterised by a sequence of brown and red-brown, calcareous clays and mudstones, with occasional beds of impersistent green siltstone and fine-grained sandstone. It was deposited between 200 and 250 million years ago in the Triassic period.
It underlies much of central and southern England and on which many urban areas and their infrastructure are built.
Although Mercia Mudstone appears to cause few serious geotechnical problems compared with other, higher plasticity, clays it is significant to the construction industry because it is frequently encountered in civil engineering activities involving foundations, excavations and earthworks.
The Engineering geology of British rocks and soils: Mudstones of the Mercia Mudstone Group provides an in-depth study of formations within the Mercia Mudstone Group using data held in the National Geotechnical Database.
The geological, lithological, geotechnical, and mineralogical features of mudstones within the Mercia Mudstone Group have been described in detail, including implications for drilling and sampling and in situ testing.
Hobbs, P R N, Hallam, J R, Forster, A, Entwisle, D C, Jones, L D, Cripps, A C, Northmore, K J, Self, S J, and Meakin, J L. 2002. Engineering geology of British rocks and soils – Mudstones of the Mercia Mudstone Group. British Geological Survey Research Report, RR/01/02.
Jones, L D and Hobbs, P R N. 1998. The Shrinkage and Swelling Behaviour of UK Soils: Mercia Mudstone. British Geological Survey Technical Report, WN/98/14.
Contact Marcus Dobbs for more information