126 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Dec. 17, 



surfaces. This mass of rock is probably the same as the double- 

 felspar rock of Roughten-gill, with larger crystals, which appear to 

 have undergone changes from chemical action. Below this mottled 

 rock, in the course of the stream, we come upon a grey felstone, well 

 developed, and succeeded by a purplish claystone which, on passing 

 downwards, assumes a porphyritic nature, containing small white 

 crystals of felspar. This last-named rock is seen immediately above 

 the moor-road to Caldbeck, and a short distance below this road the 

 Carboniferous rocks occur *. 



The felspathic rocks extend still further to the north-west. The 

 mottled rock is seen on the west side of Langlands-fell, and in it 

 copper has been partially worked. The grey felspathic traps occur 

 in Lowthwaite-fell, and from thence they extend to the north side 

 of Overwater, being well seen at Latrig-fell, which lies immediately 

 north of this small lake ; they are also well exhibited in Binsey Crag, 

 where they are principally of a porphyritic nature. Here some- 

 times they occur in the form of strata, and seem to be composed 

 of masses of felspathic ash, containing fragments of felspar-por- 

 phyry. When presenting this aspect, they have a conglomeratic 

 nature, and are excessively hard. On the north side of Binsey a 

 fine purple porphyry, with greenish crystals, is seen ; to the north of 

 this, on the ridge called Whitehouse Hill, hard grey rocks make their 

 appearance, being succeeded northwards by the Carboniferous series. 

 To the west of Binsey Crag and Whitehouse Hill there again occurs 

 a flat moory country like that before described in connexion with 

 the Skiddaw slates. 



I believe that Professor Sedgwick is disposed to regard the felspathic 

 traps of the Caldbeck-fells Range as the northern equivalents of the 

 greenish-grey rocks which, to the south, succeed the Skiddaw slates. 



5. The SJciddaw Slates of the Eastern Margin of the Lake-district. 



At the lower end of Ullswater, a small stream called " Ellerbeck " 

 enters the lake from the south ; it crosses the road leading from 

 Pooley to Howtown, and, at a short distance above, divides into two 

 branches. The more southerly branch is known as Eggbeck ; the 

 lower portion of its course is over gravel and large blocks of stone 

 derived from the boulder-clays of Doveack Moor. On ascending the 

 stream, after passing through the enclosed ground, a plantation is 

 reached which marks the boundary of the cultivated land, and above 

 which rocks are seen, in situ, in the bed of the brook. 



These rocks consist of contorted shales, dark in colour, thin- 

 bedded, and having a great resemblance to the graptolitiferous shales 

 of Dumfriesshire, but they do not present beds so highly anthracitic 

 as those of the south of Scotland ; as they are much broken up by 

 closely approximated joints, they have a very shivery character. 



On ascending the stream, above the dark shales others are seen 



* I am indebted to Mr. Joseph Peat, of Caldbeck, for directing me to the 

 several streams in this district where good sections occur, and also for informa- 

 tion concerning the igneous rocks and mineralogy of Caldbeck-fells. 



