386 



PEOCEEDrNGS OF THE GEOLOGICAL SOCIETY. 



[May 8, 



land stood low enough for the kames at Biagley to be deposited, the 

 valley of the Aire would have been a frith, through which the tide 

 may have set in opposite directions alternately, and thus the sand 

 might be bedded both uj? and down dale. I can see no other way 

 than by a tidal current setting backwards and forwards through a 

 strait in which sand and gravel can be deposited with a dip both up 

 and down dale. 



The close connexion of kames with ordinary scratched drift is 

 well seen in the vale of York. The western side of that vale con- 

 sists of low undulating hills of drift. This drift is sometimes a well- 

 scratched deposit of typical Boulder-clay, containing intercalated 

 seams of fine sand and gravel, or a deposit of scratched pebbles too 

 stony to be called Boulder-clay ; the true Boulder-clay and the 

 gravel passing gradually into one another. At other times the beds 

 consist of stratified gravel, with here and there a faint trace of 

 scratches that once existed but are now all but effaced. These 

 gravels have the characteristic shape of kames ; they either form 

 long ridges, nearly straight, or ai'e arranged in confused heaps sur- 

 rounding hollows ; but the scratched and the unscratched gravels 

 are quite inseparable from one another. 



In some gravel-pits near York, the structure of these kames 

 is well seen. There we have, at the Coplesham gravel-pit, the 

 foUowinar section : — 



Section in Coplesham Gravel Pit. 



a. Strong clay. b. Gravel. c. Sand. 



Gravel. 



Gravel, 



The upper part (A) consists of a stifi', brown, unstratified clay con- 

 taining a few scattered pebbles in its upper part, but choke-full of 

 stones in its bottom, where it rests on the lower bed (B), which is a 

 well-stratified gravel and sand arranged in the shape of a ridge, the 

 beds dipping away on both sides from the crown of an arch. 



I saw no scratched stones here ; but corresponding stratified 

 gravels on the other side of the Ouse contain numerous well-glaciated 



