Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/117

 escarpment from Melmerby scar on the north to Murton Pike on the south. This narrow line of slate is bordered on its west side by an irregular but nearly parallel range of greenstone. The breadth of both these rocks together seldom exceeds a mile, and towards their north extremity is contracted to the compass of a few yards; here they appear also much disturbed and confusedly mixed together; the spot is marked in the map as Melmerby Lane End, about one mile south-east of the village of that name. They assume greater strength in their progress towards the south, and the position of the greenstone becomes more decided on the west of the narrow line of slate. The variety of proportions in which its ingredients are found combined is quite endless; every hill, almost every block, gives a new character of it.

These rocks of slate and greenstone form two parallel narrow ranges, displaying on the surface an irregular outline, and attracting attention by the striking feature of three lofty conical pikes, distinguished by the names of Knock pike, Dufton pike, and Murton pike. Of these the former, which is the most northerly, is chiefly composed of greenstone. Dufton pike, the central one, contains both greenstone and slate; and Murton pike, which is the most elevated, and at the south extremity, appears to be composed almost entirely of slate.

We found no greenstone indeed within a mile of Murton pike, it seemed to terminate at Keisley about one mile south-east of Dufton, a spot which I shall again notice as affording a singular mass of limestone.

Though the exact limits of these two ranges might possibly be ascertained by careful and patient investigation, their line of junction