238 e. n. worth on certain alluvial deposits 



Discussion. 



Mr. Ussher stated that he had been inclined to consider that 

 the sands flanking the Bovey valley were of peculiarly local occur- 

 rence ; but the observations of Mr. Woodward as to their similarity 

 to certain arenaceous deposits on Great Haldon and the Blackdown 

 Hills, recalled to his mind an instance where, in a pit on the 

 former, sand of granitic origin, much resembling portions of the 

 sands in the neighbourhood of Newton, is shown, underlying an 

 accumulation of broken unworn chalk flints in a clayey matrix, 

 ascribed by Sir H. de la Beche and French geologists to the Plastic- 

 Clay formation. Owing to the removal of Post-tertiary deposits, he 

 was unfortunately unable to trace any connexion between them. 



The sands of which Mr. Woodward's paper treats skirt the Bovey 

 valley at heights of from less than 100 to more than 500 feet above 

 the sea-level, dippiug down the slopes of the hills at angles roughly 

 coincident with them, as gravel seams in the deposits show. Hence 

 it seems evident that they cannot have been originally deposited 

 upon their present uneven surface, but owe their position to those 

 forces of elevation and depression the prevalence of which in Devon 

 during the Post-tertiary period is elsewhere distinctly evidenced. 

 With regard to one statement, he desired further information from 

 Mr. Woodward — namely, as to the direct superposition of these sands 

 upon the clays of the Bovey valley ; for he agreed with Mr. Wood- 

 ward that the superficial deposits of the valley, including the gravels 

 of the Zitherixon pit (in which the wooden doll or idol was found), 

 were of much later date, and due to the redistributing action of the 

 stream now occupying the valley at a period when its volume was 

 much greater than at present. 



With Mr. Worth he entirely agreed in considering that Mr. Belt's 

 explanation of the gravels of Devon and Cornwall was unsatis- 

 factory; for not only were there no signs in their mode of occur- 

 rence of a general dispersion involving more or less of cataclysm al 

 action, but indications of a clear order of sequence, manifested, for 

 instance, by the gravels on the sides of such valleys as those of the 

 Exe, Otter, Taw, and Torridge, indicating successive deposition by 

 the former representatives of the present streams in their erosion of 

 the valleys, the most recent deposits occurring as alluvia and gravels 

 occupying flat tracts of land through which the rivers now flow. 



He considered that if, in addition to the evidence furnished by 

 these gravels, the raised beaches on the Devon and Cornish coasts, 

 the stony loam or head of angular debris overlying them, the 

 cavern deposits of Devon and other phenomena were taken into 

 account, an order of sequence proving physical changes might be 

 established, by which some conclusion respecting the vicissitudes 

 experienced by the counties of Somerset, Devon, and Cornwall 

 during the Pleistocene epoch might be arrived at. 



Mr. Thorpe was glad that steps had been taken for properly 

 working out this interesting district, as there were few reliable 



