GEOLOGY. 



15 



the Underset limestone from 1,125 ^^^^ is thrown down by a 

 dislocation to 1,000 feet. At Preston the succession of the 

 beds below the Middle limestone, as given to me by Mr. Craig, 

 of Aysgarth, is as follows, viz. : — 



30 eet — Middle limestone, rich in ore 



Gritstone 



Coal seam i foot thick 



Plate 



Grit 

 Flagstone worked above Carperby 



Large Plate ■ 



Thin Lime 



Strong gritstone 



Small plate 



Post, of grit 



Plate 

 20 feet — Simonside limestone 



Grit 



Plate 

 Grit 

 Plate 

 Thin lime 

 Ironstone, thin 

 Plate 

 Grit 



Small plate 

 Plate and Ironstone 

 Grit 



Small Plate 

 60 feet — Hardraw limestone 

 Grit 

 Plate 



From an elevation of 1,700 feet in Cotter Fell and the south side 

 of Lovely Seat, the Main limestone declines gradually eastward 

 to 1,025 feet at Preston, 836 feet at Leyburn Shawl, and 700 

 feet at the town of Leyburn. Through the mass of moor 

 between Yoredale and Swaledale, the course of the series is 

 nearly level or declining slightly towards the north. On the 

 south side of Lovely Seat the Main limestone is upwards of 

 200 feet lower than in Cam Fell and Bear's Head, and on the 

 north or Swaledale side of the same hill it is 1,554 feet in eleva- 

 tion, with 660 feet of the Millstone Grit beds over it. Between 

 this point and Muker the Yoredale Rocks are exposed in Cliff 

 Gill, with a total thickness of nearly 700 feet, with all the lime- 

 stones of the Hawes section present, the upper band 82 feet, 

 and the underset band with chert on the top of it, 54 feet in 

 thickness, but the lower limestones thinner than at Hawes ; and 

 the non-calcareous interpolations above the Middle limestone 

 237 feet thick, instead of 430, and those below it 210 feet 

 instead of 350. The head of the pass between the dales of the 

 Swale and the Eden is 1,700 feet in elevation, and the mountain 

 peaks that encircle it are about 600 feet higher, and here also 

 the Main limestone is between 1,500 and 1,600 feet in elevation. 



Jan. ifi 



