CoLi': — Glacial Features in Spitsbergen. 203 



1882 to 1908. The Sefstrom Glacier to the west — a sheet 6 kilometres broad 

 at its sea-front — advanced between 1882 and 1896 so as to cover Cora Island 

 and almost to reach the opposite shore of Ekman Baj'. A slight recession 

 had occurred by 1898. By 1908, a retreat of 2 km. had taken place in that 

 part of the front which stretched south-west from Cora Island ; but a large 

 mass of residual ice remained resting on the island. This was accompanied 

 by a moraine of reddish mud and marine shells, which originally must have 

 been largely intraglacial — that is, picked up and pushed forward in the body 

 of the ice. Though reduced in size, the " ice-island " remained conspicuous 

 on the west side of Cora Island when we studied the locality under 

 De Geer's guidance in 1910 (PL XY., fig. 13). The most noteworthy 

 feature was the occurrence of much of the red moraine matter on the back of 

 the tabular relic of clear ice. Shearing movements in the interior of the 

 glacier during its advance must have carried up the intraglacial moraine over 

 a part of the ice that was practically free from debris. Similar movements 

 no doubt had brought tlie ice on to the low island, as an overthrust portion 

 of the glacier, the base of which, in traversing the sea-floor, lay 50 metres 

 (say, 25 fathoms) below the surface of the water. The shelly clay thus 

 deposited on Cora Island is believed to have come from the sea-floor ; but I 

 cannot help thinking that it may equally well liave been carried across fi'om 

 the raised beaches on the western shore of Ekman Bay. Similar red clay 

 can be seen in places in the lower part of the raised beach at Cape AVijk in 

 Dickson Bay, resting directly on Carboniferous limestone. 



In any case, transport has been effected across an arm of the sea about 

 4 km. (2| miles) wide and the material has clearly been raised above the 

 position that it occupied during transit. The hummocky boulder-clay now 

 lies in part 30 metres above the sea. An uplift of mud, pebbles, and shells 

 through a height of at least 200 feet was proved by Garwood and Gregory' in 

 the case of the Ivory Glacier, which descends on to marine deposits in Agardh 

 Vale in eastern Spitsbergen. The interesting occurrence on Cora Island has 

 been discussed by G. W. Lamplugh before the British Association at Sheffield 

 in 1910, and its main features are described by Wahnschaffe.^ ■ 



The gravels with marine shells that are banked up to heights I,oOO feet 

 above the sea against the spurs of the Dublin Mountains have been often 

 attributed to subsidence of the land during the glacial epoch. I have mj'self 

 urged' that they may represent the material of pre-glacial raised beaches 



' Op. cit., Q. Journ. Geol. Soc. London, vol. liv., p. 205. 



* Op. cit., Zeitschr. Gesell. Erdkunde, Beilin, 1910, p. 651. 



^ " County Dublin, past and present," Iiish Naturalist, vol. (1892), p. 9i. 



