PROCEEDINGS OF GEOLOftlCAL SOCIETIES. 189 



wells sunk for the drainage works ; the distance between them is 350 

 feet :— 



Section No. 60. Section No. 61. 







ft. 



in. 



ft. in. 







1. 



Sui'face Soil 



. 1 



3 . . . 



....13 



Surface Soil . . 



1. 





/Brown Clay 



. 1 



9 



4 6 



Soft hght-brown Clay> 







Soft blue Clay . 



. 4 



0 









Peat . . . * . 



1 



0 









2.1 



Soft blue Clay . 



. 3 



0 







>2. 





Peat .... 



1 



0 











Soft blue Clay . 



. 2 



0 



10 9 



Soft blue Clay . . 







,Peat .... 



2 



9 









* Skull, t Celts t 

 With bones of vvhale, deer, 



ox, etc., at 15 ft. from 



the surface. 



3. Gravel (sunk into) 4 0 4 0 Gravel (sunk into) . 3. 



The surface of the marsh-laud at East Ham is 5 feet above Ordnance 

 datum (Liverpool mean-tide), or 12^ feet above Trinity high-water mark. 

 Consequently the level at which these relics were found, is one foot below 

 low water spring-tide of the district. 



Such remains might be of like age with the relics of the Scandinavian 

 Stone period or of the Swiss Lakes. They might be within the historic 

 date. Nothing could prove this point but the strata themselves. It was 

 not a little singular that on the opposite side of the river to the East Ham 

 marshes there were thick layers of cockle-shells beneath the soil in many 

 places. One of these, perhaps the most easy to hnd, occurred near 

 Lesnes Abbey, and a small section of it was exposed at the side of the road 

 leading towards tlie river. He did not mean to say that this was actually a 

 refnse-heap, like the Kjokkenmoddings, but bethought such accumulations 

 were worth examining. 



Royal Society.— Jf^rc/i 27.—" Theoretical Considerations on the Con- 

 ditions under which Drift Deposits containing the Remains of Extinct 

 Mammalia and Flint Implements were accumulated, and on their Geolo- 

 gical Time." By Joseph Prestwich, Esq. In the paper which the author 

 read before the Society in 1859, it was demonstrated that the flint imple- 

 ments occurred in undisturbed gravels commingled with the remains of 

 extinct mammalia ; but the theoretical considerations of the subject were 

 then omitted. The author now showed that in existing river- valleys, in 



s 



Section in the Valley of the Seine, a a, high-level gravels ; d, valley gravels; 

 T, present river-course ; e e, chalk-rock in situ. 



parts of England and France, two lines or zones of gravels or drift deposits 

 are met with ; one at from fifty to two hundred feet above the present 

 streams, and usually forming a terrace: the other ranging along the 

 bottom of the valleys. The elevated terraces are portions of former valleys, 

 wider and more shallow than the present ones, scooped out by other and 

 different causes than mere ordinary river-action. They are above the 

 reach of the highest floods, and no other mass of water than that flowing 

 up an arm of the sea could fill them. The Seine, at its highest flood, has 



