DESCRIPTION OF THE ISLANDS 365 



terminal ice-cliff is neither pushed out to sea nor set back any distance on the solid land, 

 but so rests on the shore that its base is often awash at high tide. At the South Orkneys 

 the glaciers of this type are characterized by the steepness and generally by the high 

 elevation of their initial ice-slopes; they are also largely circumscribed, being cut oft' 

 from their neighbours by rock ridges running athwart the line of the coast. In the 

 sounds and straits of the Palmer Archipelago on the contrary they cut sharply back 

 into the lower part of the high land behind, so that the steep initial slope is often absent 

 or ill-defined. They are characterized by their more regular shelf-like appearance and 

 great lateral development, the coasts for mile after mile being fringed by ice-platforms 

 unbroken by any rock. In his valuable account of the physiography of the Graham Land 

 region Holtedahl^ believes that ice formations of this kind must, by plucking, cut down 

 and backwards into the high land and carve out in the rock on which they rest low fore- 

 lands akin in structure to the rocky forelands or "strandflats" of the Norwegian west 

 coast. "Now" he says "as to the character of the surface of the solid underground be- 

 neath the ice there is only one natural conclusion to be drawn, viz. there must exist a low 

 foreland corresponding to the foreland ice sheet in front of the high part of the islands ". 

 For such foreland glaciers, responsible in his opinion for the low coastal rock platforms 

 on which they rest, Holtedahl proposes the name "strandflat" as being more appro- 

 priate than Nordenskj old's "ice-foot" glaciers. 



Turning now to the South Orkneys we find that in Laurie Island, where it is evident 

 from Pirie's^ description and diagrams that most of the glaciers belong to this type, there 

 can be little doubt that glacial erosion with formation of strandflats is taking place on a 

 considerable scale to-day. That it is evidently taking place on the east and parts of the 

 south coast of Coronation Island as well is shown by Plate XIX, figs, i, 2, 4, and more 

 particularly by Plate XV, figs .1,2, which illustrates small but well-developed ice platforms 

 in front of the high land on the southern side of Coronation Island. Comparing the two 

 localities, Palmer Archipelago and the South Orkneys, we find that this characteristic 

 physiographical development which is taking place in both has apparently proceeded 

 farther in the first than in the second ; for the continuity, the relative flatness, and general 

 shelf-like appearance of the foreland glaciers of the Palmer Archipelago, in contrast to 

 the lateral constriction and steeper initial grade of the South Orkney glaciers, suggest 

 that the former have already cut deeper into the underlying rock. Thus if the ice were to 

 melt in the region under consideration we should probably find at the South Orkneys, 

 particularly in Laurie Island, a system of detached coastal platforms, none of very great 

 lateral extent, and none as yet cut sharply into the mountains behind; whereas in the 

 Palmer Archipelago there would be seen continuous low forelands of great lateral extent 

 meeting the high land behind at a sharp angle. Developing under climatic conditions 

 that are largely the same for both localities it is possible that in time the South Orkney 

 strandflat glaciers will come to resemble those found in the Palmer Archipelago to-day ; 

 that the dividing ridges which now separate her glaciers and prevent their lateral 



1 Holtedahl, O., 1929, loc. cil., pp. 14-22, text-figs. 4 and 6. 

 - Pirie, J. H. Harvey, 1913, loc. cit., pp. 838-9, text-fig. i. 



