Читать книгу Flowers of the Coast - Ian Hepburn - Страница 9

A Résuméby J. A. STEERS

THIS BOOK is concerned with the ecology of the sea-coast and the seashore. The various types of ground that come under this broad title are subject not only to constant change but often to violent change. Even the hardest cliffs are comparatively unstable, and almost always subject to strong winds and storm-waves which may do much superficial damage, even if the actual rate at which the cliff retreats is, in terms of human life, extremely slow.

Great Britain has a remarkably long and intricate coastline and a long and varied geological history. Strata of nearly every period are well represented. These rocks, and the associated igneous rocks (also of very different ages) give the coast great interest and variety. We can observe the white and often perpendicular cliffs of the Chalk, the magnificent ranges of dark red cliffs of Old Red Sandstone in Caithness and Kincardine, the grey walls of Carboniferous Limestone with their flat grassy tops in west Pembrokeshire, the rapidly wasting cliffs of glacial deposits of north Norfolk and Holderness, the heavily glaciated cliffs of the whitish-grey Lewisian Gneiss, alternating with those of the brown and often spectacular Torridon Sandstone in north-western Scotland, and the granite cliffs of Land’s End and the Isles of Scilly. These are but a few examples from many; the point is that the rock type alone—quite apart from whether the beds are folded, broken, horizontal, or cut into diverse forms by marine or sub-aerial erosion—makes the coastline extremely interesting.