Rapid localized glacio-isostatic uplift at Glen Roy, Scotland

Abstract

Many studies involving measurement of the altitudes of fossil marine and lacustrine shorelines have demonstrated glacioisostatic tilting, particularly in North America, Fennoscandia and the British Isles. Such studies are normally illustrated by height–distance diagrams in which fossil shorelines are portrayed as straight lines. In some studies the shoreline-relation diagram is used to analyse and illustrate the altitudinal data1–3: before constructing such a diagram it is assumed that a simple pattern of glacioisostatic uplift has prevailed. Warping of shorelines, as opposed to uniform tilting, has been inferred in North America4–6. On the other hand, Harme7 envisaged block movements in Fennoscandia. Sauramo8 also proposed dislocations, but his interpretation was rejected by Hyyppa9. More recently the concept of the Scandinavian shield as a stable area has been dismissed10,11. Here we provide evidence from Scotland for shoreline dislocation by differential movement of blocks of the Earth's crust.