Fugla Ness (above)
Other key sites
One of the main tools for reconstructing the glacial history of an area is to examine the local stratigraphic record. Layers of till are firm indicators of the former presence of glacier ice and their fabrics and erratic content provide information about the direction of former ice movement. Where tills are inter-bedded with other sediments, such as meltwater or periglacial deposits then a sequence of events can be built up.
On Shetland, the possibility of complex stratigraphy has been greatly reduced by the erosive effects of successive ice masses. The latest glaciers tend to erode the loose sediment deposited by earlier ice masses and meltwater. Nonetheless useful information can be provided even when only two tills are superposed.
Offshore it is a quite different situation. In the northern North Sea and towards the edge of the continental shelf on the West Shetland Platform complex and thick sequences of glacial, glacimarine and marine sediments occur. Although the dating of these sediments remains at an early stage, the sediment piles represent an archive of environmental change during the Quaternary on Shetland and on the surrounding shelves.