On some Intrusive Rocks in the Neighbourhood of Eskdale, Cumberland

Abstract

Chief amongst the group of intrusive rocks which it is my purpose to describe is the granite of Eskdale and Wasdale Head, which possesses petrological characters of peculiar theoretical interest; but I shall also deal with certain minor intrusions near the foot of Peers Gill in Upper Wasdale, and with several groups of dykes which have been usually thought to be associated with the Eskdale Granite, but appear to me to have had a separate origin at a period remote from that of the intrusion of the granite. II. The Eskdale Granite . The granite comes to the surface in two exposures. The larger and more southerly of these occupies an extensive tract of country in Eskdale and Mitredale, and extends southwards as far as Beetle Fell, while it reaches to within a mile of the sea in the neighbourhood of Ravenglass. The smaller outcrop lies in the floor of Upper Wasdale and extends from Down-in-the-Dale, beneath the hotel at Wasdale Head, and up the valley to about half a mile above Burnthwaite Farm. The larger outcrop has a total length of some 12 miles and a breadth of 4 at its widest part, while the smaller mass measures about 1 mile in length by half a mile in breadth, and is roughly elliptical in form. The rock is mentioned by Clifton Ward in a paper entitled ‘ The Granitic, Granitoid, & Associated Metamorphic Rocks of the Lake District,’ and also in the Geological Survey memoir on the district. In the