ON AN ANCIENT BEACH AND BOULDEKS. 



657 



45, On the Ancient Beach and Boulders near Bratjnton and 

 Cbotde, in N. Devon. By T. M'Kenny Hughes, M.A., Wood- 

 wardian Professor, Cambridge. (Read June 23, 1887.) 



The ancient high-level beaches of the south-west of England have 

 long attracted notice. Paris * referred some of them to blown sand ; 

 Carne f and Boase % mentioned the occurrence of similar phenomena 

 around the coast of Cornwall. Godwin-Austen § described a 

 " raised beach" at Hope's Nose, and later on, in his paper on the 

 superficial accumulations of the coasts of the English Channel ||, gave 

 an account of several other deposits in different localities, which 

 seemed to him to indicate an elevation of the coast-line. The posi- 

 tion of many of these beaches is indicated by Greenough on his 

 geological map and by Be la Beche on the maps of the Geological 

 Survey. 



Among the raised beaches we generally find included the sand- 

 cliffs of Saunton Down and Middle Borough, on the coast west of 

 Barnstaple. These deposits have a further interest attached to 

 them from the occurrence at their base of lar°e boulders of various 

 kinds of rock, some of which, it would seem, do not exactly resemble 

 any rock-masses in the drainage-areas from which they could have 

 been transported to where they are now found by any kind of river- 

 action. 



Sedgwick Murchison **, Williams ft, and De la Beche have 

 described these cliffs, pointing out the similarity of the deposits to 

 those of the modern shore, and, assuming that the whole was an 

 ancient beach, of course explained its present position by changes 

 in the relative level of land and sea. It seems to have been 

 generally spoken of as a Raised Beach from the time of these 

 earlier observers till the year 1866, when Mr. Spence Bate§§. from 

 a careful examination of the sections, returning to the views of 

 Paris, arrived at the conclusion " that the entire structure conduces 

 to the conviction that the so-called raised beach is in reality the 

 undestroyed remnant of an extensive district of wind-borne sand 

 similar to that which now exists on Braunton Burrows." 



In a paper published in 1867 || j| Mr. Pengelly replies to Mr. Spence 

 Bate, and gives exact measurements taken at various points along 

 the cliffs. He is led by a consideration of the low level at which 

 various land-plants are found to infer that the tide does not now 

 often reach the level to which the remains of Balanus indicate that 



* Trans. R. Geol. Soc. Cornwall, vol. i. 1818, p. 4. 



t Ibid. vol. iv. 1832, p. 259. \ Tom. cit. pp. 259, 270-273, 320. 



§ Proc. Geol. Soc. vol. ii. 1834, p. 102. 



|| Quart. Journ. Geol. Soc. vol. vii. 1851, p. 118. 



^[ Trans. Geol. Soc. vol. v. p. 279 ; Proc. Geol. Soc. vol. ii. p. 442. 



** Ibid. 



tt Trans. Geol. Soc. vol. v. p. 287 ; Proc. Geol. Soc. vol. ii. p. 441. 



\X Eeport on the Geol. of Cornwall, Devon, and W. Somerset, 1839, p. 425. 



Trans. Devon Assoc. Adv. Sci. Lit. and Art, 1866. p. 128. 

 II |l Ibid. 1867, p. 415. 



