Tour of Snowball Earth

Scottish Geoheritage Festival October 2017 Tour of Snowball Earth -October 21/22

The late Precambrian tillites and carbonates on Islay and the Garvelleachs are the best evidence in Scotland of a major glaciation about 650 million years ago. The area has been selected as one of the top 50 geosites in Scotland and will feature as part of the Scottish Geoheritage Festival in October 2017.

Friday 20th - Arrive Islay. Introductory Talk at Port Charlotte Nature Centre

Saturday & Sunday 21st/22nd. Full day guided walks. Exact itinerary to be decided at the time dependent on group fitness, weather, estate activities etc

Day 1: A guided tour of two key localities (Beannan Dubh near Ballgrant and Fionn Phort near Port Askaig) illustrating the 650 million year old glaciation that probably covered the whole world at that time (‘Snowball Earth’).  The aim is to demonstrate the transition into the snowball event (Lossit Limestone at, review the sedimentology of the glacial deposits (Port Askaig Tillite)

Day 2: A full day visit to the remote north coast of Islay to view the classic stromatolite bioherms in the Bonahaven Dolomite plus some spectacular igneous intrusions and glacial features.

A small donation to the Islay Natural History Trust is suggested.

A less strenuous alternative to Caol Isla and Bunnahabhain will be offered if group fitness & weather dictate. 

It may be possible to charter a local boat to return walkers from Rhuval lighthouse. This would save the 2-hour return walk but will be chargeable at cost and is dependent on weather, tide and boatman availability.

For more information please email