Welcome to Islay and its wonderful variety of rocks. This website provides an introduction to the geology of the islands of Islay, Jura and Colonsay. It also includes links to events such as guided walks, and more information.
The Islay area is the best place in the British Isles to see the 1,800 million-year old metamorphic rocks (the Rhinns Complex) which underlie much of central Scotland.
It has relatively undeformed sedimentary sequences (the Dalradian) deposited from 750-600 million years ago on the margins of the ancient Iapetus Ocean.
It has the world-famous Precambrian glacial deposit (the Port Askaig Tillite) that tells of a time of severe, perhaps global, glaciation.
The island has the best evidence in the British Isles of Precambrian life in the form of fossil microbial colonies (stromatolites).
Islay has a variety of 60 million years old igneous intrusions related to the opening of the North Atlantic Ocean.
and …. the islands have a wide variety of Ice Age erosional and depositional features
Please follow these links to more pages or use the menu button