NWHG Ref. 018 — Glencoul

Location, grid reference and photograph

The site occupies a large area to the south-east of Kylesku and includes the whole of Loch Glencoul and surrounding areas to the north-east, south-west and south-east, including the prominent Stack of Glencoul. Grid Ref. [NC 236 304]–[NC 295 288].

(Figure 20) Loch Glencoul. Glencoul Thrust to the left, the Stack of Glencoul with Moine mylonites to the far right. From near Unapool. BGS Photo P5135921 — M Krabbendam.

GCR site reference, block, volume and notified feature of SSSI?

GCR Ref. 902, Moine Block, Vol. 34. Notified feature of Loch Glencoul SSSI.

Description and geological significance

The Glencoul site area is representative of the northern part of the Assynt Culmination in the Moine Thrust Belt and contains exceptional examples of thrust exposures. It is of international importance because it provides unrivalled opportunities for viewing and understanding the large-scale structure of thrust belts, particularly the incorporation of crystalline basement. At the Stack of Glencoul, mylonitic rocks associated with the Moine Thrust are well exposed and have been used for numerous structural studies.

Accessibility

The best view of the Glencoul Thrust is obtained from a layby on the A 894 near Unapool ([NC 235 320]) which is accessible to all abilities. Otherwise, a long walk of between 3 and 8 km from the A 894 is required to access the main features across very rough and undulating terrain, frequently steep and/or boggy. Alternatively, the head of Loch Glencoul can be reached via boat during the main visitor season.

Conservation

No conservation requirement due to the scale and location.

Visibility and “clarity”

The Glencoul Thrust is best seen from the layby on the A 894 where there is a large interpretation panel installed by SNH as part of the Rock Route. The important features are easily discerned from the lay-public and this view point attracts many visitors. The Stack of Glencoul is rather remote and is generally only visited by university parties. The access by boat from Kylesku is commonly used.

Interpretation and interpretation potential

The view across Loch Glencoul from the A 894 layby is undoubtedly one of the most dramatic geological views in the British Isles and the Rock Route interpretation panel is an extremely important facility. The features of the site are commonly explained to visitors on the ‘Statesman’ boat trip from Kylesku. This boat trip is also featured in the guidebook “Exploring the landscape of Assynt” No additional interpretation is required and the viewpoint and the Glencoul Thrust should certainly be included in a future Geopark guide.

Key references

BUTLER, R.W.H. 2009. Glencoul. In Mendum, J. R., Barber, A. J., Butler, R. W. H., Flinn, D., Goodenough, K. M., Krabbendam, M., Park, R. G. & Stewart, A. D. (eds) Lewisian, Torridonian and Moine rocks of Scotland. Geological Conservation Review Series, 34, Joint Nature Conservation Committee, Peterborough, 268–273.

LAW, R.D. 1987. Heterogeneous deformation and quartz crystallographic fabric transitions; natural examples from the Moine thrust zone at the Stack of Glencoul, northern Assynt. Journal of Structural Geology, 9, 819–833.