North West Highlands Geopark (2016) North West Highlands Geopark Geodiversity Audit and Action Plan 2013–2016
Additional notes: These web pages are sourced from the PDF North West Highlands Geopark Geodiversity Audit and Action Plan 2013–2016
NWHG Ref. 038 — Glen Oykel South
Location, grid reference and photograph
This small site is located in the bed of the River Oykel c .750 m north of its confluence with the Allt Sail an Ruathair, Grid Ref.
GCR site reference, block, volume and notified feature of SSSI?
GCR Ref. 1222, Caledonian Igneous Block, Vol. 17. Notified feature of Ben More Assynt SSSI.
Description and geological significance
The site comprises rock-slabs exposed in the bed of the River Oykel and is representative of the “grorudite” (peralkaline rhyolite) suite of dykes which are emplaced only in the Ben More Nappe. At this site, a 4 m thick dyke of grorudite (one of a swarm exposed elsewhere) cuts through the syenite of the Loch Ailsh intrusion, demonstrating that the Loch Ailsh was emplaced prior to movements on the Ben More Thrust and the associated emplacement of the grorudite intrusions.
Accessibility
The site is located in a remote part of Glen Oykel but can be accessed via a rough, unsurfaced track to the north of Benmore Lodge. Moderately difficult access, therefore, but no all abilities access.
Conservation
Low conservation requirement due to the location of the site.
Visibility and “clarity”
The key features are only visible once the site has been accessed.
Interpretation and interpretation potential
The site is located within a very remote area and is unlikely to be visited by members of the general public other than geological specialists/students. Interpretation potential is therefore very limited.
Key references
PARSONS, I. 1999. Late Ordovician to mid-Silutian alkaline intrusions of the North-west Highlands of Scotland. In Stephenson, D., Bevins, R. E., Milward, D., Highton, A. J., Parsons, I., Stone, P. & Wadsworth, W. J. (eds) Caledonian Igneous rocks of Great Britain. Geological Conservation Review Series, 17, Chapman & Hall, 345–393 (site description page 381).