MacDonald, J. G. and Heriott, A. (Eds.) 1983. Macgregor’s Guide to the Geology of Arran. Geological Society of Glasgow. 2024 note: Most grid references have been recently estimated. They do not occur in the original publication.
4 Descriptive itinerary
The fourteen excursions described in this section of the Guide are planned to serve as an introduction to the salient features of the geology of Arran. They vary in length and range of subject matter covered. Each excursion is illustrated by a map upon which the various exposures to be examined have been indicated by a number. Excursion 1 is the widest in its scope, introducing the beginner to examples of sedimentary, igneous and metamorphic rocks of a varied character and of diverse ages, Excursions 2 and 3 cover the ground immediately south of Brodick where sandstones and breccias of Permian age and the numerous intrusions cutting them are magnificently displayed. Excursions 4 and 5 deal in the main with the Carboniferous System and Excursion 6 with Old Red Sandstone and Ordovician rocks. Excursions 7 to 10 are devoted mainly to an examination of the metamorphic rocks (Dalradian schists etc.) on the northwest and west margins of the Northern Granite, and include (Excursion 7) a visit to the classic unconformity at North Newton. Excursions 11 to 13 are concerned with a study of the geological features characteristic of the southern half of the island. Excursion 14 is the most detailed and, in part at least, the most specialised, since it covers an area of great complexity of rock types and structures forming the northwest portion of the Central Ring Complex.
Suggestions for shorter itineraries: For those who have their own transport but a very limited time available a broad sample of the geology of the island is provided by the Road Logs in Section 5 of this Guide (p. 179). Otherwise the following abbreviated itineraries are recommended to visitors who wish to sample a wide range of geology but do not want to follow all the itineraries:
(a) Nine-day itinerary:
| First day: | Glen Rosa and Glen Shurig, Excursion 1. |
| Second day: | Corrygills and the Clauchland Hills, Excursions 2 and 3. |
| Third day: | Corrie and the Locherim Burn, Excursions 4 and 5 |
| Fourth day: | Glen Sannox and North Glen Sannox, Excursion 5 |
| Fifth day: | Catacol, Loch Ranza, North Newton and the Cock of Arran, Excursion 8, localities la to 9a, and Excursion 7, localities 1 to 17. |
| Sixth day: | Catacol, Loch Tanna, Pirnmill and Loch Coire an Lochan, Excursions 9 and 10. |
| Seventh day: | Kingscross and Glen Ashdale, Excursion 11a. |
| Eighth day: | Largybeg and Bennan, Excursion 12; and (if transport is available) Drumadoon and the Tormore shore, Excursion 14. |
| Ninth day: | Area around Ard Bheinn, Excursion 14. |
(b) Six-day itinerary
| First day: | As above. |
| Second day: | Sannox and Corrie, Excursion 6, localities 1–11, 14–17; and Excursion 4, localities 1–14. |
| Third day: | As fifth day above. |
| Fourth day: | Brodick to Lamlash, Excursion 2; Whiting Bay to Glen Ashdale, Excursion 11. |
| Fifth day: | As eighth day above. |
| Sixth day: | As ninth day above. |
(c) Three-day itinerary
| First day: | As for six-day itinerary. |
| Second day: | As for six-day itinerary. |
| Third day: | Corrygills and the Clauchland Hills, Excursions 2 and 3. |