1868.] QUATERNARY GRAVELS OF ENGLAND. 455 



May 6, 1868. 



The Rev. James Crombie, M.A., 84 St. John's Wood Terrace ; 

 Charles Judd, Esq., A.K.C., F.R.A.S., 3 Stoneleigh Villas, Totten- 

 ham ; Duncan G. ¥. Macdonald, Esq., 4 Spring Gardens ; J. S. 

 Phene, Esq., 5 Carlton Terrace, Oakley Street, W. ; and M. Thom- 

 son, Esq., College House, Southgate, were elected Fellows. 



The following communication was read : — 



On the Quaternary Gravels of England. By Alfred Tylor, Esq., 

 F.L.S., F.G.S. 



[The publication of this paper is unavoidably postponed.] 

 (Abstract.) 



Mr. Tylor first compares the gravels of the Aire Valley at Bingley, 

 of the Taif Vale between Quaker's Yard Junction and Aberdeen 

 Junction, and of the Valley of the Rhonda near its junction with the 

 Taff. He then describes the cave-section of Bacon Hole, Gower, 

 and the sections exposed at Crayford, Erith, and Salisbury, com- 

 paring the angles of deposition of gravel-beds concealing the escarp- 

 ment of the Chalk in these last three localities with the same con- 

 ditions at Brighton and Sangatte. 



By comparing the gravel-beds at different levels, and upon strata 

 of different age and configuration, he shows in what respect they 

 differ from each other. The bulk and height of the Quaternary de- 

 posits have strengthened the conviction which he expressed in his 

 previous paper (on the Amiens Gravel), that there was a long period, 

 reaching nearly to the Historical epoch, in which the rainfall was 

 excessive, and which he termed the " Pluvial period." 



These sections also lead the author to the following conclusions : — 

 (1) That the debris was deposited by land-floods, and that the mode 

 of deposition was quite distinct from that of moraines produced by 

 the melting of ice. (2) That the character of the deposits in the 

 valleys of the Aire, Taff, and Rhonda proves that they were formed 

 under similar conditions. (3) That these gravel-beds point to a 

 Pluvial period of great intensity and duration. (4) That the ice- 

 action of which there is evidence was subordinate to the aqueous 

 action. (5) That the fossiliferous Quaternary deposits have been 

 best preserved where they have been formed in cavities lying be- 

 tween the edge of the bank of a river, estuary, or sea and an 

 escarpment running parallel with it at no great distance. (6) That 

 the immediate source of the gravels was the high land adjoining the 

 rivers, whence they have been washed down by rain, with the assist- 

 ance of lateral streams, into the lower ground, where they had come 

 into contact with larger quantities of running water, had been mixed 

 with rolled materials, and spread in thick beds over the bottoms and 

 slopes of valley's or the sides of escarpments. (7) That the surface 

 of such a deposit rarely slopes at more than from 2" to 4°, while the 

 slope of the beds lower in the series nearer the escarpment averages 

 12°. The escarpment is usually concealed under a coating of gravel 

 or loess. 



