I3S 



DEVONIAN. 



Green Slates of Rame Head. — The beds, before mentioned, are 

 surmounted at Rame Head, west of Plymouth Sound, by green 

 or grey slates, with beds of fine grey quartz-veined grit. South of 

 the Cawsand trap-rock, pale green quartz-veined slates are exposed 

 on the coast forming Penlee Point. 



Picklccombe and Staddon Grits. — Towards Picklecombe Fort, west 

 of Plymouth Sound, shales intercalated with grey and red grits 

 are exposed in reefs. At Staddon Pier, east of the Sound, these 

 grits again occur ; and in both cases they are very much disturbed 

 and contorted.^ These are termed the Staddon and Bovisand 

 Grits by Mr. R. N. Worth, ^ as they occur also in Bovisand (Bovey 

 Sand) Bay, close to Staddon. Grey micaceous slates, very much 

 altered, are met with at Salcombe and Bolt Head. These beds 

 are now sometimes grouped as Archaean. (See p. 46.) 



The following Table shows the local grouping of the Devonian 

 Rocks of West Somerset and North and South Devon : — 



Mr. Champernowne has come to the conclusion that the physical 

 conditions which prevailed in South Devon during INIiddle and 

 Upper Devonian times, had a far closer analogy to those of the 

 Nassau and Belgian areas, than to those of North Devon and West 

 Somerset, so much nearer geographically. 



W. A. E. Ussher, P. Geol. Assoc, viii. 445 ; Trans. Roy. Cornwall G. S. 1S81. 

 Trans. Devon Assoc. 1883, xv. 396 ; G. Mag. 18S3, p. 423. 



