TRANSACTIONS OF THE SECTIONS. 65 
mountain chain, and is diversified by many most picturesque forms as well as 
many shapeless mounds. Crossfell and the adjoining region form the highest parts 
of the Pennine chain, and, opposite the greatest elevation of the volcanic rocks on 
the other side of the chain, ten miles distant, the basaltic bed called the “Whin 
sill” attains its greatest thickness (40 fathoms) and its greatest intensity of 
chemical action. The Red Sandstone is washed up into all the irregular spaces 
of the hills, both limestone and volcanic, thus proving its deposition after the 
elevation of the hills was accomplished. 
The volcanic band is described in detail from near Brough, in Westmoreland, to 
Hartside Fell. Murton Pike is conical, and abuts against a lofty convex cliff of 
limestone, resting also partly on its ledge above. Dutton Pike, a striking pyramid 
of 1575 feet of absolute height, and about 1000 feet from the base, with a slope of 
from 28° to 33°, is completely isolated. The rock is apparently cut off on the 
north by the great Crossgill vein traversing the Alston Moor district east and west 
for many miles, and ending at the escarpment; and the southern limit is very 
near the great independent dislocations in Fmidials and Stainmoor, which produce 
so much confusion in the neighbourhood of Brough, and even change the south- 
ward course of the Pennine Fault. 
Between the Eden New Red Sandstone and the western side of the volcanic 
band there is a narrow line, often faintly traced, of limestone and shale beds, 
dipping rapidly under the Red Sandstone, which have been broken off from the 
chain by the fault. The limestone is light blue, dark blue, brown, and almost 
white, and often crystalline. The greenstone passes into slate, grey or whitish. 
The former is a dull dark substance, varying in hardness, liable to decomposition, 
but often very compact. Analysis of specimens from Dufton Pike :— 
Greenstone. Slate. 
RATE cc oc vacs.s « a 7 Siltcn. secre esc ose .. 70:50 
Tron and alumina........ 13 Tron and alumina......,. «ccna 
WATE Gye .c. 4 2:5, c:4.0 > Dette, sects turds 5 Time rscr, chee Raa itfaresdwiy .» trace 
PROS aa ia, 2.0030 4.0.2 0 trace Magnesia ........ qo ceca une 
Loss—heating ..,......, 6:50 LGkS. rat heh sodas! dayncl a 1:50 
Alkalies and matters not found 
by difference....... alehetsis 
100:00 
On the west side of Dufton Pike occur beds of granite, apparently in round or oval 
deposits, and like that of Shap Fell. Smooth boulders of this granite, of basalt 
and of quartz rock, are dispersed on the flanks of the chain and on the volcanic 
hills. ‘here are also veins or dikes across the Jine of volcanic action, containing 
quartz, felspar, and talc. There are signs of parallelism in the process of eruption ; 
but there is no appearance of craters. The three large Pikes are striking ex- 
amples of regular forms produced by processes of degradation. 
he ninety-fathom Slip-Dike, or Tynedale Fault, is then traced from the sea to 
Hartley Burn, where the narrow line of the Newcastle Coal-field, thrown down to 
the north by the fault, disappears. A large basaltic dike accompanies the fault for 
many miles across the rivers Allen and South Tyne, at 200 yards’ distance on the 
south. Another basaltic dike passes on the north side of the fault from Choller- 
ford, crosses the Tyne thrice, and is supposed to enter the Hartley Burn district con- 
siderably north of the coal-field there. This coal-field has been worked to the 
extreme west end, where it appears to be cut off by a slip-dike running N.N.W. 
and afterwards W.N.W., and much broken and very irregular. It appears to rise 
to the W. and N.W., and the coal-beds dip for about 40 yards to the north. This 
outcrop of the Newcastle Coal-field is only three-quarters of a mile distant from 
that of Tindale Fell, in the mountain-limestone chain. It seems, therefore, pro- 
bable that the former coal-field is simply terminated by its junction with the 
Pennine chain. A slip-dike, seen near Blenkinsopp, may be the same that appears 
to cut off the coal, and afterwards to pass by the tate of Halton Lee Fell, through 
Tindale Fell, into Geltsdale. The vertical beds appear faintly, but distinctly, in 
Blackburn in this direction. The slip-dike that throws down the Tindale Fell 
oe Talkin Fell, for 40 fathoms, runs W.N.W., and appears to be confined 
, m 5 
