NWHG Ref. 060 — Stac Pollaidh

Location, grid reference and photograph

The mountain of Stac Pollaidh lies about 1 km north of the unclassified Drumrunie — Achiltibuie road, Grid Ref. [NC 108 107].

(Figure 50) Rock towers on the summit ridge of Stac Pollaidh. BGS Photo P 512989 — M Krabbendam.

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

The site is not GCR-listed but lies within the Inverpolly SSSI, although it is not a notified feature.

Description and geological significance

The iconic and dramatic mountain of Stac Pollaidh is an excellent example of an inselberg, resulting from directional glacial erosion of the Torridonian Sandstone bedrock. Highly weathered and jointed rock surfaces close to the elongated narrow summit ridge show evidence of repeated freeze-thaw processes during the most recent episode of glaciation, indicating that the summit was not actually covered by the ice at that time. Excellent examples of post-glacial scree slopes form the lower half of the mountain.

Accessibility

A car park for hill–walkers and visitors to the mountain is located at [NC 108 096] on the unclassified Drumrunie — Achiltibuie road. The mountain can be easily viewed from this car park or at many other stopping points along the road. The mountain is thus accessible to all abilities from the point of view of appreciating its form from a distance.

Conservation

Generally low conservation requirement due to the nature and scale of the feature. However, significant numbers of hill-walkers visit the mountain each year and SNH have reconstructed the access path along a new alignment around the southern end in order to avoid further human-induced erosion/degradation of the scree slopes on the south-west face. This aspect will require future monitoring.

Visibility and “clarity”

The essential characteristics of the inselberg and the peripheral scree slopes are easy to see from a distance. Stac Pollaidh is a very dramatic mountain feature which is inspiring for hill-walkers and photographers/artists as well as students of physical geography/geomorphology, geology and landforms in general.

Interpretation and interpretation potential

An interpretation panel is currently located at the main car park for hill-walkers. The story of the formation of the mountain feature, associated scree-slopes and its biodiversity is well covered. The site is featured as part of a walk in the guidebook “Exploring the landscape of Assynt”. The site is suitable for developing a guided walk. Clearly, the mountain should be included in a future Geopark guide and a programme of guided walks around the mountain could be a successful development.

Key references

BRADWELL, T. & KRABBENDAM, M. 2003. Stac Pollaidh: A Late Devensian Nunatak? Quaternary Newsletters, 100 19–25.

BALLANTYNE, C. 2010. Relic talus slopes on Quinag and Stac Pollaidh. In Lukas, S. & Bradwell, T. (eds) The Quaternary of Western Sutherland and adjacent areas: Field Guide, Quaternary Research Association, London, 131–135.