48 



The Natuealist. 



glacial beds were met, tough boulder clays, gravelly beds, and sand 

 beds. From these it has been possible to draw up a pretty complete 

 plan of the beds. In the S.W. part these prove to be alluvial sands 

 and laminated clays, forming a thin coat over the glacial deposits. 

 Only about three feet of soil were removed from the S.W. corner, the 

 depth increasing from this point. Looking at the ground-plan we are 

 immediately struck by the regular strike of all the beds from S.W. to 

 N.E. The whole appearance suggests the work of an iceberg 

 ploughing up from the S.W., and pushing these beds before it. 

 [Diagrams and photos were exhibited to illustrate the characteristic 

 points here indicated.] Floating ice, however, rather than the 

 moraine prqfonde of an ice-sheet, seems best to account for the mixture 

 of tough boulder-clays with beds of boulders, gravels, and current- 

 bedded sands. The post-glacial deposits are worked to depths of 30 

 feet and more ; in the river bed they may exceed 50 feet. The river 

 is now 60 or 70 feet above its pre-glacial bed, and probably 40 or 50 

 above the level to which it first cut down in the opening of the post- 

 glacial epoch. 



LOCAL GEOLOGY. 

 Mr. G. W. Lampltjgh, of Bridlington Quay, read an interesting 

 and exhaustive paper on " The Bridling-ton and Dunlington Glacial 

 Beds," and the Eev. E. M. Cole, of Wetwang, read a paper for Mr. 

 J. R. Mortimer on " Sections of the Drift obtained by the new drain- 

 age works at Driffield." 



SUBSIDENCES IN LAND. 

 A paper on " The Subsidences above the Permian Limestone 

 between Hartlepool and Papon," by Mr. A. G. Cameron, Geological 

 Survey of England and Wales, was read by Mr. Topley. In this 

 paper attention was drawn to the numerous forms of shrinkages of the 

 land-surface, often extending to considerable depths into the rocks 

 beneath, observable over the top of the permian rocks betwixt Hartle- 

 pool and Ripon. As a general explanation of their origin, it was 

 suggested that where the underground water, flowing over the lime- 

 stone surface, reached the margin of the sandstone, it received a check 

 whereby it accumulated, forming a chain of dams or pools along the 

 line of junction of these rocks. As denudation proceeds, hollows form 

 above, until ultimately the phenomena of the pits appear. This being 

 so, " the water bubbling and frothing all over " was explained without 

 calling in the aid of river-action. Allusion was made to the Home 

 Farm Colliery accident at Hamilton, N.B.,iu February, 1877, through 



