Arran and Bute slate quarries, Highland Border slate belt, Scotland

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From: Richey, J.E. and Anderson, J.G.C. 1944. Scottish slates. Wartime pamphlet No. 40. London : Geological Survey of Great Britain.

Arran[edit]

The slate belts of Scotland. P519813.
Map of Highland Border slate belt. P519823.

(P519813)

Maps[edit]

Six inches to the mile: Bute, Sheet 226, S.W.

General description[edit]

In Arran, the Aberfoyle Slates form a comparatively narrow outcrop at the north end of the island E. of Lochranza. They were formerly worked in two small quarries 1,000 yds. S.S.W. of Cock farm, of which the more easterly is the larger, although the face is not more than 50 yds. long and 25 ft. high (Gunn 1903, p. 148). The slates are mainly of a bluish-grey colour, but include some light-coloured greenish-grey bands. The cleavage dips to E.N.E. at 20º to 25º.

There are records of the working of the slates between the years 1773 and 1781 and some may still be seen on the roofs of houses in Lochranza. It is very unlikely that the quarries would be worth reopening, even for local use, as they are difficult of access, being situated at a height of about 1,000 ft. above sea-level, a quarter of a mile south of the summit of a rough track leading from Lochranza to Cock farm.

Bute[edit]

(P519823)

Maps[edit]

One inch to the mile (Geological: hand-coloured) Sheet 29

Six inches to the mile: But, Sheet 194. S.W.

General description[edit]

The Aberfoyle Slates cross the island of Bute in a north-easterly direction from Etterick Bay to Kames Bay. They have been quarried on a moderate scale at two localities W.N.W. of Port Bannatyne (P519823) , and have also been worked in a small opening at Ardmaleish Point, N. of Kames Bay and 2 ml. N. of Port Bannatyne.

The larger more westerly, of the two quarries W.N.W. of Port Bannatyne is situated 700 yds. N. by W. of a Church at a road junction about 1¼ ml. W., of Port Bannatyne. Access is by a rough track from the road. The quarry is about 180 yds. long and 50 to 70 yds. across. The face appears to have risen to about 50 ft. but is now much obscured, and it is impossible to make out the position and characteristics of individual seams. The slate is of grey or grey-blue type with cleavage dipping 30º S. of E. at 30º to 35º; the bedding is not clear. Some quartz veins occur. At the western edge of the quarry the slates are overlain by fine-grained flaggy green grits; some overburden is also present, but its thickness is difficult to estimate. There are probably reserves to N.N.E. A whin dyke should be encountered in this direction about 200 yds. from the edge of the present quarry.

The smaller, more easterly quarry is situated 400 yds. W. of Hillton a mile N.W. of Port Bannatyne. Access is by a good track, as far as Hillton, thence by a very rough track over a stream, the bridge across which is missing. The quarry is an oval opening about 90 yds. long, with a face perhaps originally 30 ft. high but now much obscured. A seam of apparently fairly good slate, of a grey or grey-blue colour and at least 10 ft, thick, has been worked. The cleavage-dip is to S.E. at 35º. The bedding is not clear. There are some thin quartz veins. The over-burden is light. There are probably plentiful reserves to S.W. The quarry was last worked about the beginning of the present century to obtain slates for the roof of Wester Kames Castle.