438 



PROCEEDINGS OP THE GEOLOGICAL SOCIETY. [April 22, 



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of Torr Cross. Other slates, not very- 

 dissimilar except in their less even la- 

 mination, succeed these, with the same 

 northern dip, and lead up to the meta- 

 morphic rocks of Salcombe and the Bolt. 

 The relation of the soft variegated ar- 

 gillaceous rocks to the somewhat coarser 

 and less regularly laminated reddish slates 

 on the shores of Start Bay north of Slap- 

 ton is a question not very easily decided, 

 except inferentiaUy, which, of course, is 

 not the most satisfactory method. But 

 the reddish slates of Start Bay precisely 

 resemble those at the southern extremity 

 of the Dart-river section at Kiugswear, 

 to which they appear to form a consecu- 

 tive series ; and if we trust to the dips 

 as representing the true succession of 

 the beds, they will appear to be clearly 

 above the grits of the Dart river opposite 

 Dartmouth, and of Bugford. The varie- 

 gated slates on the west, between Aveton 

 Giifard and the altered schists of the Bolt 

 Tail, on the contrary, resemble those 

 which are seen to pass beneath the grits 

 on the north at Modbury, and at the via- 

 duct near Greenway House on the Dart. 

 Following the strike of the beds from 

 Dartmouth by Woodieigh and Aveton 

 Giffard to B-egmore, and from Stokenham 

 to Thurlestone, we find that the included 

 rocks occupy on the shores of Bigbury Bay 

 not more than haK the breadth of coun- 

 try that they do on the opposite coast 

 south of the Dart ; and therefore it would 

 appear that the sharp anticHnal axes are 

 on the west, and the synclinal axes on 

 the east. As the dips are aU southerly 

 (from S. to S. 20° E.), at high angles, 

 these axes must be thrown over to the 

 north, and we thus have the same beds 

 repeated again and again. That these 

 inclined anticlinal and synclinal axes are 

 not purely hypothetical will, I think, ap- 

 pear when we consider that if we were to 

 measure the distance from the Ditsham 

 Hmestone to where the dip becomes re- 

 versed between Stokenham and Friscomb, 

 we should find it amount to rather more 

 than seven miles, which, at an angle of 

 35° only, would give a thickness of up- 



