Rock formations in the Lake District

in Granite

The geological setting of the central part of the Lake District is completed by igneous rocks which have been intruded into the various sedimentary formations. Many of the outcrops are quite small and even the well known Shap granite occu-pies only a few square miles at the surface. luxury themed boutique hotels in the lake district It is an easily recognizable rock with its pink colour and elongated crystals offelspar. Huge quarries have been opened up on Shap Fells by the side ofthe A6 road as the rock is in great demand for railway ballast, heavy constructional work and, more recently, as a road metal. A much larger outcrop of granite occurs on the southwest fringe of the Lake District around Eskdale and the approaches to Wastwater. Covering about thirty five square miles, the outcrop is sufficiently large to make a direct impact on the scenery and character of the area.

In appearance it is not unlike the Shap granite, but the felspar crystals are not so large. At one time it, too, was extensively quarried and used as a building stone. By many it was looked upon as the most attractive of the granites in the British Isles. Nowadays quarrying for this purpose has ceased and it is only in the older buildings and dry stone walls that its former widespread use can be appreciated. The lower twothirds of Eskdale below Wha House and the whole of the adjacent Miterdale occur within the granite outcrop. It also forms the foothill zone between Muncaster Fell and Bootle. This whole area is attractive, unspoilt country preserved largely through its relative isolation compared with other parts of the Lake District. The granite is not usually associated with spectacular scenery, and although rock crags do occur as, for example, about Spout House in lower Eskdale, they cannot compare with those of the Borrowdale Volcanic country. Running through the granite are vertical dykes of a harder and coarsergrained rock. That on the slopes below Whin Rigg is about fifty yards wide and can easily be picked out because of its rugged sur¬face, which contrasts so markedly with the smooth grasscovered slopes of the granite.

Close to the Eskdale granite outcrop is another igneous mass which extends from the lower end of Wastwater across Ennerdale and then to Buttermere. It measures about ten miles from north to south and has a maximum width of almost five miles. The main rock type present, termed a granophyre, floors both the valleys and occurs on the ridge tops. Between the Ennerdale and Buttermere valleys it is responsible for smooth rounded slopes like those of Red Pike , which stand out in great contrast to the rugged crags of High Stile, formed of Borrowdale Volcanic rocks. Glaciation, too, has seized upon the differences in rock type and by selective erosion has accentuated the landscape contrasts.

The third main group of igneous rocks occurs in the Skiddaw massif well to the north of the other main centres. The rock is again a granite with white felspar crystals to distinguish it from the Eskdale and Shap granites. A recent attempt to determine its age, by what is known as the potassium argon dating method, has shown that it is about 400 million years old. In spite of its great age only a small part of its original roof capping prior to emplacement has been removed, so that exposures at the surface are limited. The largest outcrop is in the valleys of the upper Caldew and Blackhazel Beck, but even here only about a square mile is exposed.

Its small extent makes it of no consequence in fashioning dis¬tinctive scenery. It is rather the slates and grits altered by contact with the intruded granite which make the most impressive features of the area. Around Bowscale Tarn, for example, the Bannerdale Crags tower above the corrie lake. From their precipitous slopes one can look northward to Car rock Fell crowned by the still distinct stone ramparts of the Iron Age Fort . The Fell is composed of a complex sequence of igneous rocks which are all hard and resistant to erosion. As a result they give rise to the rocky crags which look out over the marshy valley of Mosedale.

Author Box
Adrian has 1 articles online

Adrian vultur writes for luxury themed boutique hotels in the lake district

Add New Comment

Rock formations in the Lake District

Log in or Create Account to post a comment.
Security Code: Captcha Image Change Image
This article was published on 2011/01/11