1862.] 



HARKNESS SKTDDAW SLATE SERIES. 



127 



of a lighter colour, which are again succeeded by dark shales resem- 

 bling those below, and containing Graptolites. Drab shales are seen 

 above these in the course of the brook, having intercalated grey 

 beds, the whole presenting a shivery aspect. 



Above the foregoing shaly strata, for a short distance no rocks 

 are seen in the bed of the stream ; but a little above where the main 

 road from Barton to Martindale crosses Eggbeck, a greenish-grey 

 porphyry, with orange -coloured crystals of felspar, makes its ap- 

 pearance, and continues to occupy the bed of the stream to near its 

 source, having occasionally ashy masses intermixed with it. 



The Graptolites which occur in the dark shales of Eggbeck con- 

 sist of Graptolites Sagittarius and Didymograpsus geminus, together 

 with the branching form previously referred to. These fossils are 

 by no means abundant here, and, owing to the shivery nature of the 

 strata, they are usually in a fragmentary condition. 



Eig. 4.- 



N.N.W. 



-Section from Ullswater to Wastdale Crag (11 miles). 



S.S.E. 



Skiddaw Slates. 



Green slates, 

 porphyries, &c. 



Skiddaw Green a 

 Slates. slates, &c. 



a. Trap. b. Syenite. 



Lying west from Eggbeck is Barton-fell. At the top of this hill 

 is a greenish, ashy-looking grit ; and in the stream which separates 

 Barton-fell from Swarth-fell, the hill still further westwards, the 

 porphyries of Eggbeck are well seen, together with greenish rocks, 

 which are not porphyritic, intercalated among them, but having no 

 distinct bedding. The rocks here are rudely prismatic, and to the 

 S.S.E. they seem to pass upwards into the greenish-grey rock above 

 alluded to. 



Eggbeck is the only spot in this neighbourhood where the Skid- 

 daw slates are seen. To the north of Barton-fell and Swarth-fell, 

 both of which rise boldly above Ullswater, exhibiting escarpments 

 on their north sides, there is a comparatively low tract of country ; 

 but there no rocks in situ appear, the interspace from the south side 

 of Ullswater to the adjoining hills being covered by soil and debris. 

 The contour of the country, however, justifies the conclusion that 

 the Skiddaw slates extend some distance along the northern base 

 of Barton-fell and Swarth-fell, but that they soon become covered 

 up by the porphyries, ash-beds, and green slates, which are so ex- 

 tensively developed along the margin of Ullswater, from Howtown to 

 Patterdale, and also in the mountainous district lying southwards. 



