I’d previously assumed that the whole of Scotland was encased in ice during the last ice age, but while reading ‘Hostile Habitats’ earlier in the year I learned about the periglacial trimline. This geomorphological feature – which can be traced on many of the mountains of the Northwest – is a line marking the maximum extent of the last ice sheet. Below the periglacial trimline the rock has been scoured by glaciers; above the periglacial trimline the rock remained exposed and is often heavily frost-shattered as a result. These exposed peaks are known as nunatuks. If you’re lucky enough to have a window seat on a transatlantic flight you may be treated to a view of present day nunatuks poking through the Greenland icecap. The nunatuks of Coigach and Assynt are shown in the figure below.
This tremendous little look also contained a diagram showing the extent of the Loch Lomond Readvance glaciers, formed when the climate cooled again about 11,000 years ago. Most of them are where you’d expect glaciers to form, in high north facing coires. One of them, the one near Stronchrubie, just south of Loch Assynt in the map below, seems strangely located. I’m looking forward to examining the site in more detail next time I’m up that way.
Finally, if, like me, you enjoy a bit of beaver action, have a look at this.