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180 



GEOLOGY. 



rSeci. VI. 



the fragments would generally be qnito angular, and 

 they could not be landed in water shallower than the 

 thickness of the submerged ice, requisite to float the 



On the other hand, the boulders frozen in coast- 



and they 



ber 



ice would 



om 



could be landed on an ordinary beach, and might be 

 driven by the force of the pack high and dry, and perha,ps 

 left pilcJ in strange positions. All facts illustrating the 

 difference in the results produced by coast-ice and true 

 icebergs would be very valuable. Do the boulders fixed 

 on coast-ice, when driven over rocky shoals, become them- 

 selves scored? Wherever there was reason to beli.,e 

 that a surface had been scored by recent ice-action, a 

 minute description and drawings ought to be made of the 

 depth, length, width, and direction of the grooves ; and 



even large slabs brought home. On true iceberf^ 



when 



the fragments of rock generally fixed or lou^c^ 

 icebergs turn over, are fragments frequently seen em- 

 bedded in thuE part which was under water ; and how were 



thcv 



fixed there : 



The nature, number, si^^e, form, and 

 frequency of occurrence of all fragments of rock seen on 

 floating ice ought to be recorded, and the distance from 



their probable source. A 



raised 



5 



known from up 



orsaniG 



remains to have been latelv elevated 



would be eminently instructive. 



Do 



reat icebergs 



force up the mud and gravel at the bottom of the ^^a 



glaciers ? Can shells, 



in a shallow sea, often 



in ridges like the moraines of 



or other marine animals, live 



ploughed up and rendered turbid by the stranding of 



icebergs ? The dredge alone could answer this, i he 



means to distinguish the effects of ancient floating ice 



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