Cylchgronau Cymru

Chwiliwch trwy dros 450 o deitlau a 1.2 miliwn o dudalennau

The Caves of Gower by BERNARD MORRIs-photographs by HAROLD GRENFELL MUCH OF THE GOWER PENINSULA is composed of carboniferous limestone. This is a hard grey rock but despite its hardness it can be dissolved by water which seeps between the fissures and bedding planes of the stone, so that over many thousands of years sufficient rock is dissolved to leave the cavities, passages and caves for which limestone country is noted. During the long period since they were formed most of the caves have become partly filled with debris fallen from their roofs and walls, with soil, sand and dust washed or blown in and with hard layers of stalagmite. Excavations in such deposits during the last two hundred years have recovered the bones of animals belonging to species now extinct or no longer found in Britain. Three caves in the Penard cliffs alone contained the remains of Straight-tusked Elephant, Soft- nosed Rhinoceros, Hippopotamus, Mammoth, Bison, Reindeer, Cave Bear, Wolf, Hyaena and Lion. Today, these caves look out over the waters of the Bristol Channel. They are above high water level but must be approached down steep cliff paths or over unstable scree, with a moderate amount of scrambling required. It is certain that great beasts such as the Mammoth and Rhinoceros could not have entered the caves via the present access ways. Equally puzzling is the strange mixture of species adapted both for warm and cold climates. The Mammoth and Reindeer were adapted for life in cold sub-arctic regions, in the cheerless tundra now found in the extreme north of Europe. The Rhinoceros, Straight-tusked Elephant and Hip- popotamus were creatures of warm or warm temperate climates, unlikely to withstand the rigours even of a "mild" present-day British winter. The evidence of geology and archaeology shows that there have been slow changes in sea level and climate over a vast period of time. During the last one million years there have been a series of major varia- tions in climate. Periods of much colder conditions, "Ice Ages", have alternated with periods when the climate was warmer than it is today. It is certain also that there were changes in sea level during this period. At some times the sea would have been higher than its present level, while for long periods it lay at a very much lower level. We can perhaps picture the scene along what is now the Gower coast in one of the Ice Age periods. The present cliffs would have formed a bold escarpment at the edge of the icy, wind-swept plateau of Gower, falling towards a wide valley which stretched away to the distant hills of Devon. Many of the cliff caves would have opened on to a scree and soil covered shelf at the edge of the valley. In the valley (now the Bristol Channel) would have roamed some of the exotic animals whose remains intrigue us today. It is unlikely that the larger animals actually lived and died in the caves. The presence of their bones there is readily explained as the work of carnivorous animals such as the Wolf.