Abstract The Engineering & Physical Sciences Research Council research site at Bothkennar is located on former intertidal mudflats adjacent to the Forth estuary, which were reclaimed for agricultural use around the year 1784. A desiccated surface crust has developed in the 200 years following the reclamation, largely in response to the introduction of artificial drainage. Its formation has involved both compaction and material translocation, due to effective stress changes and to infiltration and geochemical alteration respectively. At first, new deposits accumulated in an artificial tidal lagoon and underwent autocompaction under saturated conditions. The subsequent introduction of field drains and cultivation then induced suction stresses due to evapotranspiration, leading to overconsolidation by around 150–200 kPa. These processes have also been associated with the development of an immature soil profile to a depth of around 0.7 m. The infiltration of fresh water has caused both desalination and the eluviation of clay particles. There is also a general rise in pH and fall in Eh with depth, which is associated with leaching and the downward translocation of DCB (dithionate-citrate-bicarbonate) soluble iron compounds. We conclude that the physical development of the crust was rapid and is now largely completed, whereas the chemical development is not yet completed and thus the soil profile remains immature.

Abstract The term quick clay has been used to denote the behaviour of highly sensitive Quaternary marine clays that, due to post depositional processes, have the tendency to change from a relatively stiff condition to a liquid mass when disturbed. On failure these marine clays can rapidly mobilise into high velocity flow slides and spreads often completely liquefying in the process. For a clay to be defined as potentially behaving as a quick clay in terms of its geotechnical parameters it must have a sensitivity (the ratio of undisturbed to remoulded shear strength) of greater than 30 together with a remoulded shear strength of less than 0.5 kPa. The presence of quick clays in the UK is unclear, but the Quaternary history of the British islands suggests that the precursor conditions for their formation could be present and should be considered when undertaking construction in the coastal zone.

Abstract The northerly location of Scotland in the British Isles, its mountainous terrain largely on its western side, openness to the northeast Atlantic and consequent high precipitation, ensured that it was a major centre of ice throughout the Pleistocene. Powerful ice-streams left glacial deposits on the continental shelf (Chapter 11), glaciated Ulster, northeast England, the Irish Sea Basin, notably as far south as Pembrokeshire in Wales, County Waterford in Ireland and the Wolverhampton district in Staffordshire. The main centres of ice accumulation were in the north and west of Scotland, with other centres located in the Southern Uplands and in Skye. The ‘pre-glacial’ watershed, that lay to the west of Scotland, ensured that the most spectacular glacial erosion occurred in the north and west. Deep and extensive glacial erosion effectively removed most of the deposits of pre-Late Devensian over wide areas. Such deposits are only poorly preserved in the ‘rain-shadow’ areas of northeast Scotland and in the Inverness region, along with other fortuitous preservation elsewhere as, for example, in Ayrshire, but even there the record only extends back to the Middle Devensian.