Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/118

 is not distinctly marked; the eye cannot trace it in the outline of the hills, nor is it laid open in many places by sections of the water courses.

Their order of superposition (if there be any) is equally indeterminate; sometimes they abut abruptly against each other, sometimes the slate is uppermost, at others, indeed most frequently, the greenstone.

Imperfect roofing slate has been dug at each extremity of this range, on the south at Langdon moor near Murton pike, and on the north at Middle Rig near the head of Melmerby Beck.

Slate pencils also may be obtained from many parts of the slate rock. Places named to us were Knock Fell on the east of Knock pike; Flasker; Ashlake Pike, half a mile north of Ardale water; Gale intack, Melmerby Lane End, also a field half a mile south of Murton in the valley towards Brough, and Rickargill Beck 4 miles north of Melmerby under the continuation of the escarpment northwards. I mention this last place because (if the information was correct which we received on this point from two competent witnesses) the existence of these pencils shews the presence of the slate rock four miles north of the spot where it seemed to end near Melmerby. We did not examine this line ourselves, but could hear no tidings of slate or greenstone at any place north of Melmerby, excepting Rickargill, and we know from observation that they do not exist a little further to the north at Croglin, or between Croglin and Castle Carrock.

At Swinedale Beck, between the south base of Knock pike and Dufton Fell, the slate contains one or two thin beds of blackish transition limestone, which are laid open in the water course at Caterpallet,