West Laroch slate quarries, Ballachulish slate belt, Scotland
|From: Richey, J.E. and Anderson, J.G.C. 1944. Scottish slates. Wartime pamphlet No. 40. London : Geological Survey of Great Britain.|
Six inches to the mile Argyll, Sheet 30 S.E.
The Ballachulish Slates form an outcrop about half a mile wide at Wet Laroch. This outcrop extends southwards up a steep hill-slope, but narrows and finally ends about 1¼ mls, from the shore. Near the coast it has been worked in two openings, now disused, termed the West Quarry and the Middle Quarry.
|Locality||On W. side of West Laroch.|
|Access||Adjacent to main road, railway and coast|
|Description of slate||Colour dark grey, surface even, texture medium. Pyrites (‘diamonds’) fairly abundant and of moderate size (average ¼ inch diameter).|
|Dips, with amounts||Cleavage-dip E. 21º S. at 80º. Bedding coincident or almost coincident with cleavage.|
|Joints||No general direction of joints, which are moderately abundant, was noted.|
Details of workings
About half the face, which is fully 100 ft. in height, is more or less obscured by debris, while a considerable thickness near the top is much shattered and bent. Sink, 40 ft, deep, is filled with debris. About four seams each containing some 10 to 15 ft. of good slate, are said to have been worked. On the E. side brown limy bands occur and tend to increase to S. Overburden, consisting of clayey morainic, is relatively moderate on the steep slope to S. of the quarry.
Large reserved exist to S., but their working is regarded as difficult owing to the steep slope covered with overburden, and difficulty of keeping surface water off the face in winter.
|Locality||Just E. of West Quarry.|
|Access||Adjacent to main road, railway and coast.|
|Description of slate||As for West Quarry|
|Dips, with amounts||Cleavage-dip E. 11º S. at 70º. Bedding-dip, noted near centre of quarry, S. 30ºW. at 45º.|
|Joints||As for West Quarry.|
Details of workings
A considerable proportion of the workings is under water, above which there is a face about 100 ft, in height, the lower part of which is covered in debris. Two major seams, totally 30 ft., are said to have been worked. Near the centre of the face there is a 3-ft dyke of dark whin (lamprophyre) running N. 150º W. obliquely across the face.