338 C. E. Be Ranee— On the Surface- Geology of Cross Fell. 



Ousby Dale, excavated almost entirely in Silurian rocks, overlnmg, 

 on the west, by Guns Fell, 1760 feet liigh, the top of which was 

 found by Prof. Hull and myself to be composed of Minette. This 

 valley, the level of which is above 1250 feet, splits into several 

 branches, or rather the stream (rising in the peat-covered plain 

 above) divides into several runnels, which flow rapidly down the 

 escarpment without forming a valley. Great numbers of these 

 streams do not appear to originate in springs, but to draw their sup- 

 plies from a sheet of water at the base of the peat,^ which on the 

 slopes is extremely wet, but becomes drier nearer the watershed, 

 which is an extremely flat arch in section, with the water flowing 

 below the surface as a sheet, and never differentiating into a stream, 

 the first intimation of which appears to be at the foot of the curved 

 slope, where the water breaks out and appears at, and on the surface, 

 and then eroding the peat into channels, forms the first beginning of 

 a stream. 



On the south side of the Cross Fell escarpment is the Great Dale, 

 through which flows Crowdundle Brook, which separates Cumber- 

 land from Westmoreland. At the foot of the escarpment it meanders 

 across a narrow alluvial plain, bounded on either side by cliffs of 

 Permian Eed Sandstone and Boulder-clay. 



Between the Pennine fault and the escarpment there is a terrace 

 of Lower Silurian rocks rolling in a series of W.S.W. anticlinal 

 and synclinal folds under the Old Red Sandstone conglomerate, 

 which forms the conformable bed of the Limestone series. Of 

 these beds, especially of the Skiddaw Slate, magnificent sections^ are 

 exposed, where Crowdundle beck has worked across its alluvial plain, 

 and eaten back the bluff margining the terrace into cliffs, more or 

 less covered with Boulder-beds; and at still higher elevations on 

 Grumply Fell may be noticed many large boulders of felsitic ash 

 and breccia, and also of Permian Sandstone, at 1300 feet above the 

 sea by the aneroid. 



Within the escarpment the Great Dale is extremely wild, the 

 bottom scattered with irregular heaps of rounded and angular 

 masses of rock and stones, through which the brook forces its way 

 in two and sometimes into three changing and shifting channels. 

 These stones are partly derived from cliffs, which are very fine, 

 especially those on the north or Cross Fell side, which rise 500 

 feet in a horizontal distance of 370 yards (from 1508 to 2000 feet 

 above the level of the sea) at Willie Bed, from which the gTOund 

 slopes gradually up to the^last small escarpment forming the top of 

 Cross Fell. 



Ascending the beck after leaving hard felsite, which apparently 

 rests conformably on the Skiddaw Slates at 1149 feet, not much is 

 seen until the Old Bed Sandstone is reached, dipping into the hill 



^ Every peat-covered plateau, in fact, acts precisely as an ordinary sponge filled 

 ■with water ; never giving off any considerable streams, save after rains, when the 

 spongy mass is surcharged with moisture and pours into the Dales' those peat-stained 

 moorland waters which painters love so dearly to depict. — Edit. Geol. Mag. 



* From one of these sections Prof. Nicholson obtained Agnostics Morei, Salt., and 

 other rare fossils. 



