Grey Mare's Tail
Geological Conservation Review site | GCR #2206 | Geomorphology | Fluvial Geomorphology of Scotland
Scotland's geosites are chosen because of their local, national or international importance. Take only photos, leave only footprints: avoid causing any damage to this site. You can walk almost anywhere in Scotland without the need to ask permission or keep to paths, but you have a responsibility to care for your own safety, to respect people's privacy and peace of mind and to cause no damage.
This site is a Site of Special Scientific Interest (SSSI). It is an offence to intentionally or recklessly damage the protected natural features of a SSSI, and this includes unauthorised sample collection.
The right of access does not extend to quarries, building sites or any land where public access is prohibited, or to the collection of geological samples.
Summary
This spectacular waterfall (over 200m high) comprises a series of cascades of varying size which fall over protruding bedrock benches into plunge pools below. The origin of the waterfall is due to more intense glacial erosion within the main valley (now occupied by the lower Moffat Water), assisted by the presence of a major fault, than in the tributary valley of the Tail Burn. This has left the latter as a hanging valley, draining the moraine-impounded Loch Skene. The bedrock is critical in defining the controls on the present channel as the strike of the underlying Silurian greywackes is at right angles to the flow of the water, thus accentuating the role of the protruding bedrock benches.