Geology and Landscape in the Inner Hebrides

17th to 23rd May 2008

For anyone interested in Scotland's landscape,wildlife and history, the week's geology course on Eigg has lots to offer. Under the expert guidance of John Hudson and Ann Allwright, you learn to read the rocks of Eigg as if they were the pages of a history book that spans not two hundred, but two hundred million, years.

The oldest rocks tell of a time when what we now call Eigg was occupied by a shallow gulf of the sea. You will find fossils that show the waters teemed, from time to time, with fish, shellfish and swimming reptiles, such as plesiosaurs. Later the Earth's crust split open, releasing huge volumes of hot lava. Evidence for this activity is to be seen in the terraced nature of much of Eigg's landscape, each terrace being a lava flow.

The prominent Sgurr of Eigg, also volcanic in origin, has had geologists arguing from the nineteenth century to this day over exactly how it formed. One of them was Hugh Miller, the first to find a fossil plesiosaur on Eigg, in fact in the whole of Scotland. If you enjoy fine writing, take his "The Cruise of the Betsey" (1858) with you and marvel that the landscapes, geology and even some buildings (though now ruined) are still easily recognisable from his descriptions. Click here for details of a facsimile reprint of "The Cruise of the Betsy".

The shape of Eigg today is largely due to the last big geological event to affect it: the Ice Age. You will see how glaciers scoured away the softer rocks, leaving the harder ones, like that of the Sgurr, standing proud. Post-Ice Age features include raised beaches, left high and dry when the land, relieved of its burden of ice, rose towards its present height above sea level, and spectacular landslips.

As for the wildlife, there are eagles and skuas for the bird-watcher and, for the plant-hunter, carpets of wild flowers, a profusion of lichens on trees and rocks, and semi-tropical shrubs in the former garden of the one-time owner of Eigg; so go prepared with binoculars.

The Isle of Eigg is a beautiful place to study geology at all levels. The Sgurr of Eigg commands one of the finest views in Scotland, in which all the elements of the geology of the Highlands and Islands can be seen. The Sgurr pitchstone itself is the youngest volcanic rock in the country. Its base fills a valley carved in the basalts beneath and these rest, in their turn, on fossil bearing Jurassic sedimentary rocks beautifully exposed at Laig Bay. The famous Singing Sands of the present beach are derived from them. The responses of these varied rock types to glacial erosion since the ice age and to marine erosion and landslip forces since, have shaped the present landscape and determined man's use of it.

Day outings will explore the geology of the Jurassic sandstones, with basalt dykes, at Laig Bay and the singing sands; limestones with fossils at the north end of the island, basaltic lavas with their gas bubbles and columnar joint-pattern, and the Sgurr pitchstone ridge.

Weather and ferries permitting, you will visit the nearby Isle of Muck for views of the Sgurr from the south, Jurassic oyster beds and further igneous intrusions. The local geology will be put into its regional context in evening sessions and there will be plenty of opportunity to see the birds and plants of the island.

No previous geological experience is necessary. However, long walks are involved and participants must be fit for walking over rough, hilly terrain and rocky shores.

Older children are welcome, but participants should be aware that they are fully responsible for their own safety, and that of children accompanying them, at all times.

Tutor: Professor John Hudson

Professor John Hudson (Ph.D. Cambridge), recently retired from the University of Leicester, has over 40 years experience of studying the Geology of the area and has been the author of several papers on the subject. He is a contributor to extra mural courses. John knows the island well and has led many field study groups to Scotland and the Alps.

Cost: £360