Bedrock geology and physiography of the Monadhliath Mountains

The Monadhliath Mountains comprise of an extensive area of plateau in the Central Highlands of Scotland, which is bounded to the north by the Great Glen and to the south by Strathspey. The region is located immediately to the northwest of the Cairngorm Mountains, to the north of Creag Meagaidh and to the northeast of the Ben Nevis Range, forming a nearly continuous area of upland from Glen Roy westwards to where the A9 crosses Slochd Summit (Fig. A). The upland consists of rounded summits and is dissected by at least twenty-five key catchments. It is divided to an extent in two by the Corrieyairack pass, forming a much smaller area of upland in the west, to the north of Glen Roy, and a larger (main) plateau in the central and eastern part of the region. This main plateau slopes downwards towards the north, with the altitude of the plateau edge ranging from 900 m in the south, with individual summits as high as 945 m (Carn Dearg, NH 636 024), to 600 m in the north. As a result, the main watershed runs from west to east across the southern edge of the plateau, and this asymmetry is manifest in short, steep catchments on the south side of the plateau, with the majority of the plateau draining northwards or eastwards within large catchment areas. Valleys draining the plateau to the south tend to have steep backwalls separating the valley floor from the plateau above whilst catchments in the north gently rise onto the plateau, often with no backwall. This asymmetry has significantly affected the form and dynamics of glaciers in the region and is discussed further by Boston (this guide).