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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Nov. 20, 



some influence in producing the contortions. Above these contortions, 

 beds of sand and gravel, without any apparent stratification, are often 

 succeeded by others in which it is distinctly horizontal. 



The conditions which appear to explain these phsenomena best 

 are : — 



1. The imbedding of masses of floe-ice (not icebergs), varying 

 from 6 to 50 feet in thickness, in the till, and their being fixed beneath 

 the water, as similar masses were found fixed in the viscous mud by 

 Sir E. Parry, who speculates on them, at the suggestion of Captain 

 Sabine, as the cause of underground ice in cold countries. 



2. An irregular surface of till caused by the imbedding of these 

 masses of ice, the upper surfaces of which were probably also 

 irregular. 



3. The covering, as the coast subsided, of the ice, thus fixed under 

 water, with thin alternations of laminated clay and sand, followed by 

 massive sand and gravel. 



4. The melting of the ice, on the return of a milder climate, 

 beneath a superincumbent mass of sand and gravel more than 300 

 feet thick. 



5. The vertical pressure of this mass resolved into a lateral force 

 in the vicinity of the parts lately occupied by the ice (now cavities, 

 or weak places filled with the subsiding strata), so as to squeeze 

 together the walls bounding these spaces in the till previously occu- 

 pied by the ice-blocks. This lateral pressure would be analogous to 

 the creep in coal-mines, where, on the removal of the pillars, it is not 

 that the roof sinks, from the pressure of the superincumbent mass, 

 but the floor rises. 



These views may be perhaps better elucidated by diagrams of the 

 different stages of the process by which the contortions were brought 

 about. 



Figs. 3, 4, & 5. — Ideal Sections, illustrative of the conditions which 

 may have given rise to the Contortions of the Strata in Cromer 

 Cliffs. 



Fig. 3. 



