K. Edwards C.

Collins New Naturalist Library


Скачать книгу

administration the Peak National Park is managed by a central authority in the form of a Joint Planning Board consisting of 27 representatives, of whom 18 are appointed by the constituent county authorities and the county borough of Sheffield, and the remaining nine by the Minister of Housing and Local Government. The Peak Planning Board has its own technical department at Bakewell under the direction of a Planning Officer. This form of administration is the only example of the method originally envisaged for the national parks although in one or two other instances the form adopted approximates to it. On the whole in the case of The Peak it has worked successfully. Certainly, by excluding a number of urban centres situated on the fringe of the Park, general planning problems connected with the location of industry and urban growth and re-development have been considerably reduced, enabling the Planning Board to devote its attention more wholeheartedly to the special interests of the Park.

      REFERENCES

      PILKINGTON, J. A View of the Present State of Derbyshire (2 vols). (1789)

      RHODES, E. Peak Scenery, or the Derbyshire Tourist. (1818)

      GLOVER, S. The History, Gazetteer and Directory of the County of Derby. (1829–1833)

      DOWER, J. Report on National Parks in England and Wales. H.M.S.O. (1945)

      Report of the National Parks Committee. H.M.S.O. (1947)

      Report of the National Parks Commission. H.M.S.O. (annually since 1950)

      MONKHOUSE, P. J. Some National Park Problems. Jour. of the Town Planning Inst.: 43 (March, 1957)

      National Park Guide No. 3: Peak District. H.M.S.O. (1960)

       THE ROCKS AND THEIR HISTORY

       The hills are shadows, and they flow

       From form to form, and nothing stands;

       They melt like mist, the solid lands,

       Like clouds they shape themselves and go.

      ALFRED TENNYSON: In Memoriam

      A WANDERER returning to his native village in the Peak District finds his favourite haunts unchanged. The dales and streams, cliffs, hills and moors are all just the same as they were in his youth. If, however, he has studied the rocks they tell him that this peaceful, enchanting scene is but an episode in a long and eventful story which moves so slowly that for the brief period of his lifetime it seems to have been at a standstill. His going and coming have been no more than the flicks of a fly’s wings. That story is recorded for him in the rocks of the district; in the limestone of the uplands on the south; in the grits capping the moorlands of the north and forming the ridges which girt the uplands on either side; and in the shales which underlie the fertile vales that lie between the areas occupied by these two types of rock (Fig. 2, see here).

      THE FOUNDATION ROCK

      Out in the open, beyond the bounds of the stone lily forests, lay coral reefs. These were produced by the combined activities of myriads of polyps. Superficially they resembled modern reefs but the structural details of the individual corals were strikingly different. Surrounding the forests and reefs were spacious wastes of mud formed from the shells and bodies of minute organisms which fell in a perpetual drizzle from the waters overhead. Burrowing in the mud or crawling over its surface were many worms and other creatures that fed upon the mud or caught the drizzle as it fell. These latter included lamp-shells, a type of animal that is scarce today but was then varied and numerous and played a much more important part in the economy of the sea floor. Like cockles and mussels their bodies were also enclosed in shells, often prettily shaped and ornamented. They were usually small shells but some were giants a foot or more in diameter.

      Of special interest were certain curious molluscs belonging to the far-off ancestral stock of the Pearly Nautilus which lives today in the waters of the Pacific Ocean. Like this, they had shells which were divided into a succession of chambers separated by thin partitions. One large type is known as Orthoceras because its shell was straight and not closely coiled like that of the nautilus. Provided with a battery of tentacles round its mouth and with an apparatus for jet propulsion, it preyed upon fishes and other more peaceful creatures. The Goniatites were much smaller and their shells were closely coiled. In them the partitions between the chambers were folded, sometimes in sharp angles (gonia=angle) which suggested the name. These beautiful little creatures may be pictured as spending their days flitting or crawling over the coral reefs and browsing upon the coral polyps.

      Fig. 2. Geology of the Peak District. A–B is the line of the section shown in Fig. 4 (see here)

      The shells of all these animals added their quota to the deposits that were being laid down upon the sea floor. Nevertheless, though the sea was shallow, it did not become filled, for its foundations were subsiding at about the same rate as the deposits were accumulating. Thus it came about that they ultimately attained a thickness of nearly 2,000 feet.

      A temporary but fascinating feature in this submarine scenery was the occasional presence of small volcanoes. The ashes which they shot forth into the waters above settled down and became mixed with the mud beneath. Sheets of lava, full of steam bubbles, were poured out and flowed far and wide over the sea floor (Fig. 3, see here). The dark-coloured rock into which these lavas solidified is known as Toadstone and has a striking appearance due to the fact that the bubbles have been filled with a white mineral.

      All the deposits described above consolidated and became the limestone which forms the Derbyshire upland. It is sometimes called the Mountain Limestone but to geologists it is known as the Carboniferous Limestone.

      THE LATER ROCKS

      The northern shores of the Carboniferous Limestone sea lay 200 miles away and stretched across the centre of the Scottish region. Scotland, at that time, was part of a great North Atlantic continent drained by large rivers flowing southwards. The general geographical picture thus presented was not unlike that of the United States with the Mississippi flowing into the Gulf of Mexico. These rivers carried the debris formed by the destruction of the uplands and by the rain washing the plains into the sea. Deltas of grit and sand were formed and banks built out along the shoreline.