360 Geological Society : — 



It is evident from the condition of most of tlie implements that 

 they have been imbedded in some matrix which has produced an 

 external change of structure and colour. In the case of the river- 

 gravel sites the question presents no difficulty. Three classes of 

 implements have been found ; (i.) where the flint stiU shows some of 

 its original colour; (ii.) those of which the surface has turned from 

 black to white, has been altered in structure, and acquired a bright 

 patina, and which show no trace of wear ; (iii.) those of which the 

 flint has also lost its original colour, but has been stained, and is 

 with or without patina ; these are generally much rolled. The 

 characters of the first call for no comment. Those of (ii.) and (iii.) 

 are very marked, and there is no difficulty in referring each to a dis- 

 tinct matrix. The implements of class ii. have been imbedded in a 

 stiff" brick-earth, generally of a reddish colour, and those of class iii. 

 seem to have lain in ferruginous beds of sand or gravel. Reasons 

 were given for supposing the surface to have been once covered with 

 a deposit of clay or loess, since denuded except where preserved in 

 pipes, and that a continuous plane descended from the high range 

 of the Lower Greensaud to the Thames valley, which has since been 

 lowered 300 feet or more. It was also shown that the high-level 

 deposits were formed anteriorly to the post-glacial drifts of the 

 Medway- and Thames-Valleys. It is probable that the loess is a 

 deposit from flood- waters, and that some of it may be referred to the 

 Medway flowing at a higher level ; but the highest deposits cannot 

 be so accounted for, and the author referred to the possibility of glacial 

 action, without insisting on it. The deposit on the Chalk-plateau 

 is abruptly cut off" by the river-valleys, and the rudest forms of im- 

 plements, such as those of Ash and Bower Lane, occur on this 

 plateau at from 500 to 550 feet, and the author thinks they may 

 possibly be of Pre-glacial age. The changes which have taken place 

 in the physiography of the district, and the great height of the old 

 chalk-plateau, with its clay- with- flints and southern drifts point to 

 long intervals of time, and to the great antiquity of the rude im- 

 plements found in association with these drifts. That the removal of 

 the material indicates the existence of agents of greater force than 

 those operating under the present river regime closes up the time 

 required for the completion of the great physical phenomena, though 

 the author's inquiry tends to carry man further back geologically 

 than is usually admitted. 



February 20.— W. T. Blanford, LL.D., F.E.S., President, 

 in the Chair. 



The following communications were read : — 



1. "On the Cotteswold, Midford, and Yeovil Sands, and the 

 Division between Lias and Oolite." By S. S. Buckman, Esq., 

 F.G.S. 



After giving a short sketch of the work and opinions of other 



