Guide to the Geology of Islay

This guide describes 12 varied excursions on Islay that tell the fascinating story of Islay’s geological past from 2 billion-year old gneiss to the Ice Age. The geology of each walk is described at an introductory level with maps and photographs and the book also contains an introduction to geology section. For those with some geological background there is a section describing Islay’s geological framework in more detail with some key references for further reading. The walks range from leisurely rambles to more demanding longer excursions – most of which are readily adaptable with shorter easier options.

Previous Editions
This book was first published in 2015 and minor revisions were incorporated into a reprint in 2017. Further revisions were made in the 2021 edition (published during the Covid-19 lockdowns) at the same time as the publication of the companion Volume II - which contained four further excursions on Islay, plus six on Jura and three on Colonsay.
The 2025 Edition
This new (4th) edition is a substantial rewrite and reorganisation of the book, and incorporates some of the excursions from Volume II. Some excursions in earlier editions have been removed but are still available on the companion website at www.islaygeology.org. Background material has been updated.
There are now separate books for Colonsay and Jura.
This new edition has benefited from 10-plus years of leading guided walks and feedback from walk participants and from readers of the books. Many excursions have been shortened and where appropriate divided into smaller sections (e.g. 2a, 2b). Notes on accessibility for those with limited mobility have been added.