ABSTRACT

The process of detachment and displacement of large blocks of rock that have fractured along joints and bedding planes (Figure J.1). Joints are exploited by freeze–thaw processes, opening as a result of basal shear stress imposed on the glacier bed. Visible displacements range from a few centimetres to several metres. These blocks may have striated tops. Detachment of blocks of coarse Cambrian sandstone along vertical joints and low-angle bedding planes in the Rhinogydd (Rhinog Mountains), Snowdonia National Park, Wales. Ice buried these mountains at the Late Glacial Maximum, and ice flow was from east (left) to west (right). https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315373157/95d5ad9e-a71d-4f11-a609-2c025b95638b/content/figj_1.jpg"/>