The glacial succession in lowland Northern England

Abstract

Abstract The landscape of Northern England has been subjected to glacial activity several times during the Quaternary period. Successive ice sheets may have ‘swept clear’ the bedrock surface in places, but may also have incorporated materials from previous glaciations into later formations, and eventually into the present cover of glacial till. Hence, almost all the till materials now existing over Northern England were deposited during the last major ice sheet glaciation, which is known as the Late Devensian or Dimlington Stadial. These glacial tills are engineering soils, and the variable and often complex successions in which they occur have frequently led to problems on civil and mining engineering projects. Many theories have been proposed to explain the complex distribution and succession for the Late Devensian tills, which have involved the waxing and waning of the ice sheets, variations in the directions of ice flows, and other changes in the glacial and post-glacial environments. This paper attempts to summarize the published research and compare this with the authors' own experience and observations gained mainly from opencast coal mining operations in the exposed lowland coalfield areas of Cumbria, Northumberland, Tyne & Wear and County Durham. Finally, the implications for ground investigations, plus the design of stable excavations and other earthworks, are briefly discussed in the light of this experience.