Coire Gabhail
Geological Conservation Review site | GCR #1278 | Geomorphology | Mass movement
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
The Lost Valley of Glen Coe is blocked by a massive talus cone, resulting from a double rock avalanche, which fell from the slopes on the NW side within the last 2000 years.
Here a massive collapse of a cliff in Precambrian metamorphics has resulted in a huge debris cone mantling the lower part of the slope. The largest blocks are 500-1,000 cubic metres or more. The debris cone closes off the valley, which, therefore, cannot be seen from Glen Coe. Upstream is a coarse-grained alluvial flat, consisting of material of which the downstream progress has been impeded by the debris cone. Under normal flow conditions, streams from the surrounding area sink into this deposit, to emerge as a combined flow from beneath the boulders on the down-valley side of the debris cone.
Site information
Access
The parking area at NN171569 in Glencoe is the most convenient for the Lost Valley path.
Further information
https://www.walkhighlands.co.uk/fortwilliam/lostvalley.shtml
Link to a walk description
https://www.geograph.org.uk/photo/4809158
A view up valley from part way up the NW slope
Related geosites
Overlaps with:
Carol Pudsey
Oct. 18, 2024
LiDAR image of the talus cone. Illumination is from the NW. The slide scar shows up very well on this image. Image reproduced with the permission of the National Library of Scotland.
Carol Pudsey
Oct. 18, 2024
Oblique satellite image looking WSW up the Lost Valley with the talus cone on the right. Contains OS data © Crown copyright and database rights 2024.