460 Mr. Austen on the 



fine fissile slates which compose the base of the hill appear in one place to arch over, 

 and the carbonaceous beds set on, at the summit. They occupy a similar position 

 from Skeriton to Holne Bridge, where the deep valley of the Dart cuts through 

 both deposits nearly at right angles, and we might expect a good natural section ; 

 but the strata here are much disturbed by trap, which breaks out along the bed 

 of the stream. At the point of junction both rocks are nearly vertical, or if there 

 be any inclination, it is in favour of the infraposition of the carbonaceous beds : 

 on the north bank, however, and at a very short distance, as near the entrance to 

 the woods, they are to be seen dipping gently north, and for a considerable space. 

 In the ascent from Ashburton to Buckland the fine-grained fissile slates dip south 

 for some distance, till at length they arch over, as in the Hembury section, and 

 the carbonaceous rocks set on with a south dip at the crown of the hill. The sec- 

 tion at Rew Mill affords httle information, but it should be visited by any one in- 

 vestigating the structure of the country. At Place, near Ashburton, the carbo- 

 naceous rocks, for the first time, come in contact with the great band of lower lime- 

 stone, and on the north side of the great quarry they seem to rest on its surface. 

 From this point they again retreat, and form the high barren tracts known as Ash- 

 burton, Ramshorn, and Goodstone Downs. At New Inn, the two rocks are not seen 

 in juxtaposition, but at two points not very distant the carbonaceous beds are either 

 horizontal, or have a gentle northern dip, and the fine slate rock has a steep south- 

 ern pitch. 



On the opposite side of the Bovey valley an interesting section was exposed, at 

 the time the new house opposite the Chudleigh Rock was built : the excavations 

 were altogether in perfectly horizontal carbonaceous shales and sandstones. A well 

 was sunk at the same place (PL XLII.fig. 6.), and it was then seen, that these 

 beds were only about fifteen feet in thickness, resting on the edges of highly in- 

 clined claret-coloured slates, dipping in the same direction as the Chudleigh lime- 

 rock, and such slates as from Chudleigh to Barton may be seen at several places 

 to underlie the limestone. In this section we are reminded of that at Landue Mill 

 (p. 459, fig. 11.), and also of the Rydon sections (p. 458, figs. 9, 10.). The breadth 

 of slate, which in position is inferior to the Ashburton limestone, and is interposed 

 between it and the boundary-line of the carbonaceous rocks, is very unequal ; 

 yet if the latter dip beneath the rocks of South Devon, we must be prepared to 

 admit, that whilst at one place they are in contact with that limestone, yet, at only 

 a short distance, they dip beneath a great thickness of slate, which is undoubtedly 

 inferior to that limestone ; besides which, the outline of the carbonaceous rocks 

 does not conform to the strike of the slates and limestones. 



The evidence from sections leans towards the priority of the South Devon deposits, 

 but it must be admitted that the structure of the country is obscure, from great 

 disturbance ; the present elevated position of the carbonaceous beds along the 



