GLACIOLOGY OF THE SOUTH ORKNEYS. 853 



stationary. That it is not in actual retreat is shown by the absence of any morainic 

 stuff beyond its termination. Direct measurement failed to bring out any advance in 

 eight months, but the movement of these glaciers is so slow that measurement over a 

 longer period may show some. 



On the west side of the Bay there has been little or no advance over the raised 

 beach there. The ice-sheet there is such a short one that, under the present conditions 

 of precipitation and gathering ground, it has, I think, attained its greatest possible 

 development, and is now stationary if not actually retreating slightly, as the character 

 of the moraine would seem to indicate. 



The terracing and elevation of the moraines in the cirque inside Point Martin and 

 that near Point Thomson point more definitely to some recent shrinkage of these 

 particular glaciers. 



Evidence of a former much greater extension of the glaciers is not wanting, and 

 in this respect the South Orkneys are like all other portions of the Antarctic regions 

 from which reports have within recent years been obtained. They are, at the present 

 time, comparatively lightly glaciated compared with what they must have been in a 

 previous " great ice-age " or " glacial period." 



In the first place, the whole outline of Laurie Island is suggestive of ice action and 

 sculpturing on a scale much greater than that which the present-day glaciers could 

 accomplish. 



Secondly, the presence of numerous roches moutonnees and islands of rounded 

 outlines all round the coast testify to the past greater extension of the ice. Of these 

 may be mentioned the island in Scotia Bay inside Point Martin, which is about 30 

 feet in height, and separated by a channel which is only about 3 feet in depth at low 

 water. Its general outline is well rounded, and there are grooves on the surface which 

 can only, I think, owe their origin to ice action. Actual striae were not found, but 

 this is hardly to be wondered at in a region of rapid rock shattering. Near the head 

 of Fitchie Bay is another island with similar features, indicative of the passage of an 

 ice-sheet over it. Delta Island, which is now cut off from the mainland by a channel 

 nearly ^ mile wide and 10 fathoms deep, has a similar rounded outline, and on its 

 summit, 90 feet high, I found several rounded boulders of a type of greywacke- 

 congiomerate not found in situ on the island, but occurring on some islets lying to the 

 north-west in the direction of the head of the bay, and on the mainland nearly oppo- 

 site. An extension of the ice-sheets large enough to override Delta Island cannot 

 be accounted for by either increased precipitation or lessened wastage, taken conjointly 

 with the present configuration of the land. For such a condition to have been possible 

 the land must have stood at a considerably higher level than it does at present. 

 Previously, therefore, to the latest movement or movements of elevation of the land, 

 there must have been one of much more extensive depression. 



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