The Volcanic Region of Auvergne
THE VOLCANIC REGION OF AUVERGNE. By CANON T. G. BOKNEY, D.Se., LL.D.. F.R.S., etc., late Professor of Geology in University College, London. (Read July stll, 190L) UVERGNE, SO far as my experience goes, is the most A interesting region in France, if not in Europe. It can teach the geological student more about the natural history of volcanoes than the Eifel, or even than the neighbourhood of Naples, though not a single vent is now in action. Impressive as Vesuvius must be during an eruption, we have then to con template it from a respectful distance, so that, although I would gladly have witnessed this, I probably learnt more from being able to stand on the crater rim. Auvergne offers to our examination a wonderful series of preparations, the handiwork of nature, illustrative of the anatomy of a volcano, from crater-cones as perfect as that of Monte Nuovo to ruins as complete as those on the Fifeshire coast. These will principally attract your attention during your visit, but they do not exhaust the geological interests of the region. The volcanic cones rise from a great upland plateau-a huge insular mass of ancient, and to a large extent, crystalline rocks surrounded by Secondary and later strata. Depressions in this plateau were occupied towards the middle of the Tertiary era by extensive lakes, which were gradually filled up by beds of sand stone, marls and freshwater limestones, the earlier of which are contemporaneous with the Headon, Bembridge and Hamstead beds of our country. You will frequently come across sections of them, especially on the western flank of the broad valley of the Allier, sealed up sometimes under sheets of basalt.
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