LATEST VOLCANOES IN THE BRITISH ISLES.

[From The Liverpool Mercury, 26 December 1895, p. 2]

The presidential address in connection with the Geological Society of Glasgow was delivered by Sir Archibald Geikie, the Director-General of the Geological Survey of Great Britain.

Sir Archibald Geikie said his first duty was to thank the members of the Geological Society for the honour conferred upon him some time ago in electing him their president. He had a keen interest in the society. It was now more than 30 years since that connection began, and one of his earliest papers was published in the first volume of their transactions. Although he had no prepared address to deliver to them that night, he proposed to speak to them on a subject that had occupied him closely for the last 20 years, and more particularly the last seven — the story of the last volcanoes in eruption in the British Isles. Our islands were especially fortunate in the wonderfully complete record which we had within our borders of the history of volcanic action, and these were nearer than the time of the soft clays on which London was built. There was an almost continuous line of volcanic eruption along the western border of the European Continent. Our country was placed on what one might call the critical line of the European Continent. He proposed to sketch rapidly the story of the last volcanoes. These were active along the great line of valleys between the Outer Hebrides on the west and the mainland of Scotland on the east, and they extended from the South of Antrim right through that hollow, through the line of the Inner Hebrides, and on to the Faroe Islands. During the last two years he had been able to extend his researches amongs those rocks in the Faroe Islands, and he had been specially interested to find that the story of volcanic action was told there even more fully and more clearly than it was within our own islands, a result partly due to the difference of climate, greater denudation, and the greater height. The Icelandic geologist — for there was really only one — complained that geologists in their text-books and in their memoirs had been in the habit of quoting Etna and Vesuvius as types of volcanic action, and pointed out that in Iceland they would find the most potent forms of volcanic activity. He sympathised with that geologist, for he found that the story of our own volcanic history was more clearly made known by the study of the Icelandic volcanoes. One of the first features that struck them in looking at the history of the modern Icelandic volcanoes was that they did not form mountains like Etna or Vesuvius, but were the production of great fissures. When a volcanic eruption was to take place the ground seemed to have been rent into long, rectilinear fissures, of which two series at least had been discovered — one running in a north and south line, and the other running from south-west to north-east. In some cases the lava had risen up through these fissures, and flowed out tranquilly now to one side and now to the other. Most frequently it happened, however, that the lava formed great long lines of volcanic cones so close together that they actually touched each other. From the base of these cones the lava streams flowed now to the one side and now to the other, and solidified over the surface. As each eruption occurred the surface was again covered over, and so altered the topography of the country. In some cases the intervals between the outpourings of lava would be very considerable, and along the western coast of Skye and the west of Mull there was found a red layer with one of dark, almost black, rock on the top of it. Sir Archibald Geikie referred to the fact that last year, when yachting among the Western Islands, he discovered some new facts of considerable importance in considering the volcanic action in that region. Last year he also visited the Faroe Islands, and was able at one part to trace distinctly no less than five old volcano vents which had been completely buried by about six, eight, or perhaps even ten thousand feet of volcanic material. He also referred to a visit which he was able to pay to St. Kilda this year, and to get to the junction of the two masses of rock. He found the black gabbro riddled with a network of fine light-coloured rock, such as was found in Mull of Skye and Rum, but on a much larger and grander scale than in any of these islands. He hoped to be able to make a more thorough examination next year, if the weather would permit him. The volcanic period of which he had been speaking belonged to a very recent geological period — and belonged to a time actually later than the soft clay on which the city of London was built. He concluded by referring to the interesting shores of the Faroe Islands, where the imagination, which was apt to be carried away by the contemplation of scenery so splendid, was always checked by those solemn, unmoved lines always in front of them, and where they could actually obtain numerical data to control them. (Applause.)

Information
Sir Archibald Geikie (1835-1924) - biography from NAHSTE
Sir Archibald Giekie (1835-1924) – another biography from Scottish Geology
Sir Archibald Geikie, The Scenery of Scotland (1887) – an online edition prepared by Dr David C. Bossard
Geographical Evolution: An Introduction – text of an 1879 lecture by Geikie