I.—The Building up of the North Atlantic Tertiary Volcanic Plateau

Abstract

It is many years ago since Sir Archibald Geikie pointed out that the Tertiary basalts of the Western Isles of Scotland and North-East Ireland were remnants of plateaux built up of lavas extruded from fissures after the manner described by von Richthofen. In historic times fissure eruptions have taken place in Iceland, and in The Ancient Volcanoes of Great Britain a chapter is included on “The Modern Volcanoes of Iceland as illustrative of the Tertiary Volcanic History of North-Western Europe” (1, p. 260). Whilst little remains to be added in support of the very definite analogy exhibited in the nature of the lava streams themselves, the equivalent of the thin bands of red rock so typically intercalated in the Tertiary series has not been particularly examined, and I have visited Iceland in order to study the red beds themselves and search for their counterparts in the modern lava deserts.