Raised shorelines of Jura, Scarba and NE Islay

Abstract

A geomorphological investigation is made of the raised shorelines of Jura, Scarba and NE Islay, Scottish Inner Hebrides. The raised shore features consist of various terraces, beach ridges and coastal platforms. Ground levelling of approximately h,000 points indicates a complex sequence of inter-, late- and postglacial shoreline displacement.In order to understand more clearly the origin of raised coastal terraces and beach ridges and their altitude relationships to former sea-levels a study of modern coastal landforms was undertaken. Particular attention is paid to the origin and regional altitude distribution of modern beach ridges and the seaweed Pelvetia canaliculatus.Much attention is devoted to the nature, age and origin of several raised coastal platforms. Consideration of these features is preceded by a discussion, on the nature of platform development in polar and non-polar areas. A discussion of strandflat origin is also presented. Case studies of several prominent glacial landforms in the study area are included. The results of these investigations are combined with a limited study of glacial striae and erratics in a discussion of regional glaciation and deglaciation. The results of the glacial landform studies in conjunction with those obtained from raised shoreline investigations indicate a complex pattern of deglaciation.