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.
Figures & Tables
A revised correlation of Quaternary deposits in the British Isles
Realization that continental records of Quaternary rocks were more complex that hitherto believed came with the re-interpretation of oxygen isotope stratigraphy in the late 1960s and early 1970s. This necessitated a comprehensive re-evaluation that has been assisted by the emergence of new geochronological methods for terrestrial as well as land-sea correlations. The current state of such correlations is presented in this revised set of proposals for correlations in England, Ireland, Scotland and Wales, which also includes the Quaternary geology of the continental shelf. Correlation with the global standard of oxygen isotope stratigraphy enables the significance of British lithostratigraphical units to be appreciated in a wider context that includes the evolution of the climate system on the margin of the northeast Atlantic Ocean. It thus provides timely British data for the international palaeoceanographical and palaeoclimatological community and the correlations proposed are primarily on Milankovitch timescales. But their appearance coincides with the early stages of a paradigm shift to the search for both terrestrial and land-sea correlation on millennial timescales and then on centennial and decadal ones. This is the first of many similar terrestrial and land-sea correlations.