Abstract Evidence from seismic profiles, sidescan and multibeam sonar surveys and sediment cores reveal important information about the depositional history of Scotland's fjords during the last deglacial transition and the subsequent Holocene. Devensian glaciation removed pre-existing sediments both inside and outside the fjord basins, and deposited a diamict over much of the subsequent erosional surface. Glaciomarine sequences deposited during the initial retreat of this ice margin are mainly preserved in the sea area outside the fjords. Younger glaciomarine units present within the fjord basins are often attributed to the later Younger Dryas re-advance (12.8–11.5 ka BP). Younger Dryas ice reworked Devensian sediments, depositing terminal moraines at the mouths of a number of fjords and glaciomarine units within the basins during its retreat. Ice margins oscillated throughout deglaciation, although the latter stages of post-Younger Dryas retreat may have occurred rapidly with topographic pinning an important factor in determining the style of retreat. Holocene records from the fjords are limited, but tentatively support the onshore evidence for a tundra-style landscape in the earliest Holocene, followed by a warming of the climate and, latterly ( c . 2000 ka BP), increasing humidity. In the more recent past, human activities such as deforestation, fishing, aquaculture and industry have been recorded in the fjord sediments.

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.