GLACIOLOGY OF THE SOUTH ORKNEYS. 861 



account. An occasional piece of rock fallen from the cliffs above might be noted, but 

 there was nothing to be seen like the great accumulation of debris which has been 

 figured as lying on the ice-foot in some parts of the Arctic regions ready to be carried 

 ofi" when the ice-foot was broken and swept to sea in summer. 



Sea Ice. 



Although the sea around the South Orkneys is, as a whole, frozen over throughout 

 the winter, there was no time during our stay there when some open water could not 

 be seen, and the land-floe over the innermost part of Scotia Bay, inside of a line joining 

 Point Davis with Point Martin, was the only part which did not get broken up some 

 time or other during the winter. 



In most places the floe was composed of old hummocky ice cemented together by 

 young bay ice, and the interstices between the hummocks more or less filled up with 

 snow (direct fall and drift from the land). Pressure ridges were to be seen in places, 

 the highest actually noted being in September on the outer side of Ailsa Craig, where 

 some of the ice was piled up against the rocks to a height of about 20 feet. 



Some thicknesses noted of the one season's ice-floe were : — 15th June, Scotia Bay, 

 23 inches; Uruguay Cove, 18 to 20 inches, 15th August, Wilton Bay, 27 inches. 

 A considerable part of this thickness, however, represents snow accumulation on the 

 surface ; below this one comes on soft slushy ice, and not much more than the lower- 

 most third is composed of really hard ice. The greatest thickness of ice formed at 

 Wandel Island, as observed by Gourdon (23), was 25 cms. 



The same author attributes marvellous transport activity to the land-floe ofi" 

 Graham Land, in the way of carrying off material which has rolled down on to it from 

 the clifls, and which has been frozen into it below from the beach or from the bottom 

 of shallow water (24). Practically no evidence of this form. of activity was noticed 

 at the South Orkneys, but it may be noted that two pebbles of granite with red 

 felspars (a rock not found in situ in the South Orkneys) were picked up on The Beach 

 at Uruguay Cove, evidently transported there through the agency of floating ice (pack- 

 ice or icebergs). 



That pack-ice drifting with the tides and hurled hither and thither by the wind 

 and waves has a considerable action in the way of rock polishing is evidenced by the 

 accompanying photograph of rocks on the shore at Point Geddes (Plate X. fig. 2). 

 Some of these polished rock surfaces showed strise, indirect evidence of scratching by 

 stones frozen into the under surface of the pieces of floe ice. 



Glaciation of Coronation Island. 



But little can be said of the conditions here as, except for one landing for a few 

 minutes on its shore in Lewthwaite Strait, the island was only seen from the deck of 

 the Scotia coasting at some little distance ; and experience showed, in the case of Laurie 



