Nethermost Pike - Geology and Mining

Geology and Mining

Geologically the summit of the fell forms part of the Deepdale Formation, (principally volcaniclastic sandstone) underlain by the dacitic lapilli-tuff of the Helvellyn Formation. The geology of much of the Lake District is the Borrowdale Volcanic Group, of which Nethermost Pike is part, and is late Ordovician in age. The eastern cliffs of the range, including those of Nethermost Pike, are rich in base minerals. When these rocks weather they form areas of fertile soil, which together with the area's inaccessibility and climate provide suitable conditions for plants of biological importance.

Mining was carried out in Ruthwaite Cove, and the remains of several levels and some shallow open workings are visible near Ruthwaite Lodge. These excavations were made in a search for lead-bearing galena, and are believed to have been worked in the 16th century. Further leases were taken out in 1784 and 1862; the last known operation was in 1880.

North east of the summit the scene is repeated in Nethermost Cove, where the Eagle Crag Mine was mined for its lead and zinc. The vein which was exploited forms a visible gully on Eagle Crag, and was worked both above and below ground over an altitude of 300 metres (980 ft). The vein is surrounded by rocks from the Borrowdale Volcanic Group, which dates from the Ordovician. Large dumps of veinstone are found in the area as a result of the mining. They contain, among other minerals, crystallised tetrahedrite, which is not believed to be able to be seen or collected anywhere else in Britain. Eagle Crag Mine has a history of working similar to that of Ruthwaite Lodge.