Gartally Limestone Quarries

Also within

Inverness County

Condition (NatureScot)

Geology & landscape

Rock Type: Limestone, Schist

Description

GARTALLY LIMESTONE QUARRIES Gartally limestone quarries are situated on the north side of Glen Urquhart, 3 km west of Drumnadrochit, by Loch Ness. The main interest of the site lies in its contribution to the understanding of ‘skarn’ type calcium-silicate rocks and their formation through metasomatic processes (movement of chemical components between areas of rock by transport in a fluid). Within the site there are excellent exposures of pure and impure metalimestones (limestones altered by heat and pressure). These are surrounded by kyanite schists which contain blue kyanite (aluminium silicate) crystals up to 10 cm long. Areas of these rock types have reacted together, during deep burial in the Earth’s crust, to form a relatively uncommon rock type known as a ‘skarn’. Skarn rocks appear to have formed from both limestone and schist ‘parents’ and the presence of these skarn rocks is the reason for the large number of mineral species. The site contains over 60 mineral species including a number of comparatively rare calcium-silicate minerals, some of which are present as large crystals and a number of which are extremely rare in Scotland. The site is therefore also of considerable mineralogical interest. In the quarries, skarns are generally complex combinations of calcium-magnesium-iron silicates (typically comprising actinolite, calcite, chlorite, diopside, epidote and mica) together with quartz, plagioclase and titanite. Although less common, monomineralic skarns (comprising bands of rock made up of a single mineral type) have been recorded including zoisite rock, fine specimens of which can be found in the quarries. Gartally also has research potential for investigating the relationship of its ‘Albynian’ rocks to the surrounding Moine rocks, and the site may contain clues to the relationship between the Moine and Dalradian successions.