Corrieshalloch is one of the most spectacular box gorges in Britain, demonstrating the effect that water and ice can have on a landscape.
During several episodes of glaciation in the Quaternary ice ages, between 2.6 million and 11,500 years ago, a large glacier filled the Loch Broom valley. Glacial meltwater flowed along natural faults in the bedrock, carving out a gorge approximately 1.5km long and 60m deep.
The combination of mudstones (types of rock made from mud and silt) and sandstones in this area are known as the Moine rocks. They formed a particular type of fine-grained rock called mylonite, which splits easily and contains vertical faults and cracks. Large blocks of this rock were carved out by the torrents of water. The rocks are quartz-rich – you can often see white streaks (quartz veins) in them. These were formed by hot liquids circulating through cracks in the rock.
Today, through the gorge’s narrow and steep-sided length flows the River Droma, dropping 100m over the course of its ¾-mile journey in a series of waterfalls, the most dramatic of which is the 45m Falls of Measach. This waterfall’s Gaelic name is Easan na Miasaich, which means ‘fall of the place of the platters’. This refers to the smooth, rounded boulders (that do very much look like platters) that make up the river bed above the falls.
