Looking towards Maiden Pap from Scaraben, across the Appalachian-type terrain

erosion surfaces

tors

deep weathering

Streetmap extract

Langwell Forest

Significance: an ancient inselberg landscape that draws the eye across the plain of Caithness

The spectacular scenery of the Langwell Forest is not primarily a result of glacial erosion. The inselbergs, ridges and valleys relate to much earlier land surfaces: the sub-Devonian surface and Tertiary erosion surfaces. The conglomerate hills are ornamented by wart-like tors.


Godard's (1965) map of erosion surfaces in the Langwell Forest. 1. Faults 2. Break of slope at the edge of the quartzite. 3. Break of slope at the edge of Devonian conglomerates. 4. Sub-Devonian surface expressed as gentle slopes. 5. Sub-Devonian surface expressed as steep slopes. 6. Scottish Surface 7. Pliocene Level 8. Gorge.

The sub-Devonian landsurface has emerged from beneath its cover of Devonian breccia, conglomerate and sandstone. Generally restricted in area, it nonetheless defines slopes of varying inclination that were eroded almost 400 million years ago. The continuous northern face of Scaraben is one such ancient escarpment, although the absence of cover rocks from its summits requires that these hill tops were isolated by later erosion (Godard, 1965).

The main ridges are developed in resistant quartzite and form a striking Appalachian terrain. Later erosion surfaces extend to the flanks of the ridges and record prolonged phases of erosion. The present elevation of the erosion surfaces reflects to the progressive uplift of the Northern Highlands over the last 60 million years.