426 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [April 22, 



repetitions oblique to their line of strike, join on the Hamoaze with the 

 argillaceous rocks of Polbathick and Anthony, and range eastward 

 by the south of Egg Buckland to Hamerton Ball and the vicinity of 

 Ivy Bridge, where they are broken through by the granite of Har- 

 ford. Much of this slate is red or claret-coloured, especially in the 

 vicinity of Keyham, Stoke, and Ford Park ; and the gritty bands 

 associated with them further to the west appear to have entirely 

 thinned out before reaching the Hamoaze. To the eastward of Ivy 

 Bridge and the granite, the beds curve to the north-east, resting 

 on the volcanic rocks of South Brent, which are altered by the 

 granite ; and they include, on the same line of strike, as we ad- 

 vance to the north-east, other bands of igneous rock, together 

 with the limestones of Buckfastleigh, Ashburton, Bickington, and 

 Ash Hill. These limestones dip to the east and south-east, at 

 angles varying from 15° to 20°, but they are much broken by north- 

 west and south-east faults. The slates on the west of the limestone 

 are uniformly argillaceous, and often very evenly laminated, and 

 appear everywhere to dip under the limestones. The manner in 

 which these lower rocks are brought against the Culm-measures has 

 been already described, as also the position of the beds west of 

 Ashburton, which, near the town, dip towards the volcanic rocks 

 and limestones ; but at Horsehill and at the corner of the lane leading 

 up to the Druids' Parm they are thrown over to the north, beyond 

 which the bedding appears to be nearly vertical ; and they contain 

 Spiriferaclisjuncta,Petraia hina,Atliyris concentrica, CJionetes sordida, 

 Orthis interlineata, and a species of Gyathocrinus ; and in all proba- 

 bility these light-coloured beds, thus thrown under the Culm-mea- 

 sures, may not be very far below the base of the limestones. 



As we foUow the slate-beds westward of the southern extremity 

 of the granite at Ivy Bridge along their line of outcrop to the 

 north-east, they become less and less inclined, as seen in the rail- 

 way-sections between Ivy Bridge and Totnes ; the lower beds, as 

 they range northward, follow the course of the volcanic rocks and 

 limestones of Dean Church, Buckfastleigh, Ashburton, and Bick- 

 ington, dipping to the east and south-east at angles which do not 

 average more than 12° or 15°, and seldom exceed 25° ; while the 

 higher beds pass by Black Hall, near IS'ew Bridge, on the Avon, 

 where they are fossiliferous, to Sandwell, and thence to Dartington, 

 north of Totnes. Thus the belt of rocks opens out, and the beds, 

 being thrown down more or less horizontally .oy the faulting on the 

 north-west of the Ashburton range of limestones, undulate broadly 

 over the country towards the coast at Torbay, supporting the lime- 

 stones of Dartington, Berry Pomeroy, Marldon, OgweU, Kingskers- 

 well, and Torquay, and the minor patches of Sandwell, Paytor, 

 Woolstone Green, &c. Although occasionally purple, the beds are less 

 frequently so than they are further to the westward, and grit bands 

 appear to be absent. 



The evidence of the superposition of the slates to the Ashburton 

 limestones appears to be free from ambiguity, notwithstanding the 

 faults which cross the beds on the line of strike. The limestones 



