Significance: a possible Scandinavian erratic on Orkney.

This large gneiss boulder is found on Sanday. It originally rested 200 m west of Saville but was then moved to near the farm of Scar. The Saville Boulder has a distinctive mineralogy dominated by oligoclase and penetrated by threads of actinolite and accompanied by hornblende. It bears affinities with Scandinavian gneisses (Peach and Horne, 1880; Wilson et al., 1935).  Although the presence of the boulder has been cited as evidence for Scandinavian ice reaching Orkney, only one other Scandinavian erratic is known on Orkney. It is possible that the boulder was ice-rafted from Norway into the North Sea and later entrained by Scottish ice and carried to Orkney. An alternatively source in Sutherland has been suggested (Rae, 1976).

The Stone o’ Scar, Sanday: Orkney Image Library

Glacial erosion

Glacial Landscapes

  • Glaciation of Westray

    Westray is the furthest northwest of the Orkney islands. The total area is 47 square kilometres, not huge but the irregular shape gives it a long coastline of almost 80 kilometres, a good place to look for glacial striations. The bedrock of the whole of the island is made up of the cyclical Rousay Flagstone Formation. ...

  • Glacial Deposition

    Glacial deposition is largely confined to low-lying areas on Orkney, where thicknesses of till may exceed 10 m. The glacial deposits drape the landscape, smoothing its outlines. Ice-marginal features are largely unrecognised outside Hoy ...

  • Glacial erosion

    In the gently-dipping sandstone terrain of Orkney, it is often difficult to pick out classic landforms of glacial erosion. Low-lying areas often show a pronounced SW-NE grain to the topography, parallel to the main direction of ice sheet flow. ...

  • The Ice Age in Orkney

    During the periods of maximum cold in the Quaternary, major ice sheets covered Scotland. An ice stream hundreds of metres thick curved out from the Moray Firth to cross the plain of Caithness and flow over Orkney towards ice limits close to the edge of continental shelf.