240 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 22, 



Dale, from the eastern side of which (the Pennine escarpment) 

 several small rivulets flow, and by their junction form the stream 

 called Ousby Dale Beck. In one of these small rivulets Skiddaw 

 slates make their appearance, dipping N.N.W. 70°, or under the 

 green rocks of Cuns Fell. This local exposure of Skiddaw slates is 

 very small, being succeeded immediately on the west and on the 

 south by rocks appertaining to the greenstone and porphyry series. 

 There is, near this spot, but a little to the south of it, a small area 

 of syenite, which is now being worked. 



The ridges on the south side of Ousby Dale (namely, Windy Gap, 

 Hawse Crag, Sharp Shears, and Kit's How) are all composed of yel- 

 lowish-grey porphyry resembling some of the porphyries which make 

 their appearance in the lower portions of the green rocks overlying 

 the Skiddaw slate in some parts of the Lake-district. To the south 

 of these ridges the country, for a short distance, is comparatively 

 flat ; and at Ashlock Syke the same yellowish-grey porphyries are 

 seen lying upon the upper soft shales of the Skiddaw slates, which 

 are highly cleaved here, but the strata seem to be nearly vertical. 

 Ashlock Syke is the position of an anticlinal axis. Between Ash- 

 lock Syke and Ardale Beck, which lies about half a mile south from 

 Ashlock Syke, the area is made up of low hills composed of por- 

 phyry ; and at Ardale Beck, which flows by the village of Ousby, 

 the porphyry is again found having the same relations to the under- 

 lying Skiddaw slates as at Ashlock Syke. The Skiddaw slates at 

 Ardale Beck aff'ord Graptolites belonging to the genus Tetragrapsus. 

 From Ardale Beck, for a short distance S.S.E., the area occupied 

 by the Lower Silurian rocks becomes greatly narrowed, in conse- 

 quence of the Upper Old Bed Sandstone and the overlying Carboni- 

 ferous rocks of Cocklock Scar on the E.N.E. coming nearly into con- 

 tact with the same rocks on the W.S.W., which form Bank Eig. 

 In the intervening narrow area the Skiddaw slates cannot be dis- 

 tinctly made out ; but a» short distance southwards, on the south- 

 east side of Kirkland Beck (a stream which probably marks the 

 S.S.E. boundary of this Skiddaw slate area), hard green rocks make 

 their appearance and form the hUl called Wjiihwaite Top. These 

 green rocks resemble those of Cuns Fell, but they are somewhat more 

 compact in their nature, and they cannot be distinguished from 

 the green rocks of Barton Fell, near UUswater, at which place they 

 come into contact with the Skiddaw slates *. Bocks appertaining to 

 the same green series occur to the S.S.E. of Wythwaite Top. They 

 form Moray HUl and Grumpley Hill, but, as seen in these latter 

 elevations, they are more porphyritic than in Wythwaite Top. These 

 three hiUs form the west and south-west base of Cross Fell, under 

 which the green and porphyritic rocks extend. Their S.S.E. 

 boundary here is the Crowdundle, a stream which separates in this 

 area the counties of Cumberland and Westmoreland. 



3. The Lower Silurian HocJcs of the North-east of Westmoreland. 

 — On crossing the Crowdundle Beck into Westmoreland, the outline 

 of the country presents a strong contrast to that of the area on the 

 * Vide Quart. Journ. Geol. Soe. vol. xix. p. 127. 



