﻿8. V. Woodyjun. — American and British Surface- Geology. 487 



which, where it did not sweep them out altogether, twisted them up 

 in a violent manner with other sands on which they had reposed. 



Can any one contend in the face of this that sands would be left 

 undisturbed by glacier-ice moving over them with vast pressure ? 



In describing the morainic chalky clay, of which the Upper Glacial 

 in East Anglia is formed, as having arisen in part from droppings, I 

 have, until now, spoken of the dropping agent having been bergs, 

 but it has since struck me that I have been to that extent in error. 

 I was led to this view because, while it seemed to me clear that the 

 morainic matter was dropped from floating ice, I was pressed by 

 the impossibility of floe (or sea surface-formed) ice attaching itself 

 to morainic material extruded in deep water. 



In the case of this chalky clay, however, though the evidences of 

 its having arisen in part by the droppings of the material from 

 floating-ice are to my mind conclusive, yet we fail to find evidences 

 in it of the action of grounding bergs, such as is so conspicuous in 

 the case of the Contorted Drift. At the same time the general bearing 

 of the facts connected with the accumulation of the chalky clay 

 seems to me to indicate that during it the sea in East Anglia was too 

 shallow to give rise to bergs, for these only break off where the water 

 is deep enough to buoy up and break oif the glacier termination. It 

 is only some of the Greenland fiords where the water is very deep 

 that thus give rise to bergs, for in others the glacier ending in shallow 

 water melts in the sea, and fills up the fiord with its moraine.^ 



We must, I now think, infer that the agent by which this dropping 

 was accomplished was floe ice packed in winter around the glacier's 

 termination which froze to the bank of morainic material at the 

 glacier's foot, and so carried it away in sheets and masses during 

 summer. 



Eesuming now our examination and enumeration of American 

 Glacial phenomena, we find that the Erie clay, which in its lower 

 part is unstratified like the Upper Glacial clay of East Anglia and 

 of the North of England, and the Scottish Till, is similarly full of 

 rolled debris ; and it is described by Prof. Newberry as passing up 

 in Ohio into laminated beds which he attributes to the deposit of 

 the finer material ground up by the glacier-ice and suspended in the 

 water of the basin. The interbedding of material ground up by 

 glacier-ice in ordinary mud in the form of streaks of chalky silt, 

 may be distinctly seen in the Contorted Drift of Cromer Cliff", as we 

 follow it north-west from Cromer towards Weybourne, that is to 

 say, towards the place where, during the formation of this Drift, the 

 glacier discharged into the sea. In the chalky clay (or Upper 

 Glacial) of East Anglia, owing, as it seems to me, to the shallowness 

 to which at that stage of the Glacial period the sea had in that 

 part of England become reduced, we do not encounter this feature ; 



' Brown, Journal of the Geographical Soc. for 1871, p. 351. Mr. J. W. Tayler, 

 also, in the same journal for 1870, p. 228, says that numerous fiords in Greenland 

 have been so filled up by the moraines extruded by the glaciers, that boats hardly 

 find depth of water enough to ascend them, whUe one of the glaciers, that north of 

 Frederickshaab, which is 15 miles wide, and ends, not in a fiord, but on the open 

 coast, has formed a beach at its base with the moraine it extrudes. 



