6 Mr. Phillips on a Group of Slate Rocks 



most part in pasture, open and little concealed by woods, it will probably be 

 admitted that unusual facilities are afforded for g-eological investigation. 



The plan of description of this district which I have adopted is to notice in 

 succession the phenomena presented by each of the streams as it crosses the 

 line of country, and to introduce in their place the appearances on the moun- 

 tain sides. 



Lunesdale. 



The river Lune, having collected its waters from the slate tract of Langdale 

 Fells and Shap Fells and the limestone surfaces about Orton, runs through 

 a deep glen by Hougill Fells, and exposes the rhomboidal rocks which con- 

 stitute the upper division of Westmoreland slates. At Crook of Lune the 

 slate is procured in large tables, whose cleavage planes decline steeply to the 

 south, and have the "bate" grain or false cleavage dipping to the north. 



The Rother, which flows into the Lune below Sedbergh, draws likewise its 

 supplies from both slate and limestone ; but its main channel is in slate till the 

 neio'hbourhood of Sedbergh, where it divides rocks of red conglomerate very 

 similar to those which the Lune, after running some miles further in slate, 

 crosses above Kirby Lonsdale. 



The stream which flows by the village of Barbon into the Lune originates 

 on the margin of Dentdale, and runs along nearly the line of parting between 

 limestone and slate, till, where the slate of Casterton Fells fronts that of Bar- 

 bon Beacan, the limestone turns off to High Crag and Gragreth. Along 

 most of this line the limestone, where near the slate, is strangely dislocated, 

 and not unfrequently appears quite vertical, though in the carboniferous hills 

 above on the east, the beds are nearly horizontal. 



Leaving these beds the water divides a slate range for about two miles, and 

 exhibits some pretty cascades ; but suddenly, on the western side of it, en- 

 counters a line of dislocated limestone ranging toward the south, at Barbon 

 Chapel. Below this the channel is excavated in beds of old red conglomerate 

 almost down to Beckfoot. 



The Lune, after receiving Barbon Beck, flows between rocks of micaceous 

 slate which present a very interesting occurrence of organic fossils. 



AVe remark on the face of the rock here a single decomposing line, parallel 

 to the micaceous partings or cleavage, but intersected by vertical joints in two 

 directions, meeting at angles of 64° to 74°. This is a layer of shells converted 

 to calcareous spar or exposed in the state of casts. A spiral elongated shell 

 having the general appearance of a Turritella is the most abundant; with it 

 occur small striated Terebratulse, a larger and shorter spiral shell resembling 

 in contour some species of Melania, and an unascertainable bivalve. 



