588 REV. E. HILL OX WELLS IN WEST SUFEOLK BOULDER-CLAY. 



main sources were usually at the base of the Clay — a base which 

 was extremely irregular. He asked the Author how, as the wells 

 stopped at the water-beariug stratum, he could be sure that this 

 was, in all instances, intercalated and not an underlying bed. It 

 was essential to know the level of the ground at the different wells, 

 and this would no doubt be given in the paper. The component beds 

 of the Boulder-clay would vary according to the surface passed over 

 by the ice, and may, therefore, include long trails of sands and 

 gravels, and are necessarily local and irregular. He hoped that the 

 Author would continue his observations. 



Dr. Evans agreed with the Author in regarding the mixed 

 character of the Boulder-clay of Suffolk and some of the features 

 that it presents as being hardl}'- consistent with its being merely 

 the result of a coating of land-ice. In illustration of the perme- 

 ability of the beds at certain spots, he cited the deep circular pits 

 or meres in the neighbourhood of East Wretham, Thetford, which 

 were due to the dissolution of the underlying Chalk by water 

 charged with carbonic acid having forced its way through the Clay. 

 The level of the water in these meres depends upon the saturation 

 of the Chalk, and the bottom of what in one year was a deep pool 

 might in another year be cropped with turnips. 



Mr. .Clement Reid observed that intercalations of seams of sand 

 were almost universally characteristic of the Boulder-clay, and 

 helped to render it somewhat pervious to water. He was unable to 

 follow tViO Author's argument, that irregularities in the deposits 

 proved that the Boulder-clay could not have been formed under ice. 



Mr. Charlesworth said that at Saffron Walden in Essex, on the 

 borders of West Suffolk, the Boulder-clay is now being quarried on 

 an extensive scale for the purpose of making in combination with 

 Chalk what is there called " Portland cement." The denudation 

 of the Chalk and Oxford Clay has largely contributed to this 

 Boulder-clay at Saffron Walden ; and sections of the deposit are 

 displayed of extreme geological interest. 



Mr. ToPLEY called attention to the researches upon the glacial 

 geology of the Eden Yalley carried on by Mr. Goodchild, who 

 believed (as does Mr. Reid for Norfolk) that the irregular beds of 

 gravel and sand occurring in the Clay were formed within or 

 under the ice-sheet, the gravel, &c., having been washed out of 

 the Clay into hollows of the ice during partial or local melting 

 of the ice-sheet. 



Mr. Goodchild said that similar intercalations of sands and 

 gravels in the Boulder-clay were common in the North. He re- 

 minded the Society that he had proposed an explanation of the 

 origin of such deposits many years ago in the Society's Journal and 

 elsewhere (Quart. Journ. Geol. Soc. vol. xxxi. (1875), and Geol. 

 Mag. for 1874). 



The President referred to his own early work in the Boulder- 

 clay and the abundant evidence whicb he had everywhere found of 

 intercalated nests and layers of sand and gravel in that deposit. 

 He had always been accustomed to regard these intercalations and 



