684 ME. E. J. GAEWOOD ON THE [NoV. 1 899, 



Another interesting point to be noticed in connexion with these 

 nunatakkr is their effect on the en glacial moraines brought 

 down by the ice-sheet. In several cases where a nunatak pro- 

 truded from the ice, the overriding of the upper layers and the 

 heaping-up of the ice on the impact-face of a nunatak caused the 

 moraine-material, interstratified in the lower layers of the ice, to be 

 brought up and deposited on the surface in a manner similar to 

 that recorded in connexion with the Greenland ice-sheet.^ (See 

 PI. XLVI, fig. 2.) 



Attention is here called to this action, because it appears probable 

 that the upward motion of this material is produced in identically 

 the same way as was shown to occur in the case of raised-beach 

 material brought up by the advancing front of the Ivory Glacier in 

 the paper previously cited,^ — the obstruction exerted on the lower 

 layers of the glacier by the ice-talus in the one case being repre- 

 sented in the other by the submerged portion of the nunatak. 



Under this category I was at first inclined to place the material 

 which forms one of the most interesting medial moraines of 

 Nordenskjold Glacier. It consists of a row of large rounded and 

 polished blocks of hard Archaean granites, many of which are 

 4 to 6 feet in diameter. They could be seen stretching away up the 

 glacier to its source in a large nunatak of Carboniferous rocks, which 

 separates the main mass of the glacier descending from Mount 

 Chydenius from the smaller glaciers to the south. These blocks 

 were almost perfectly rounded, and occurred at intervals of many 

 yards (PI. XLYIII, fig. 2) ; they were entirely free from admixture 

 of angular debris, and had undoubtedly travelled in or beneath the 

 ice. They may have reached the surface by elevation against the 

 nunatak as described above : unfortunately the thick weather 

 which we encountered during the exploration of this ice-sheet 

 prevented me from deciding this question ; but, judging from a 

 distant view which I afterwards obtained from the coast, I am 

 inclined to think that they originated in a different way. 



The blocks appear to belong to an earlier period of glaciation, when 

 the ice-sheet covered much higher ground than at present, and had 

 therefore a different radiating-point. During this period the blocks 

 must have been stranded on the surface of the nunatak as part 

 of the ground-moraine of the ice-sheet, and strewn over the surface 

 much as are the hyperite-boulders observed by me 1500 feet up on 

 the plateau of the Sassendal. As the disintegration of the Carboni- 

 ferous rocks takes place, these Archaean blocks are hurled on to 

 the glacier below, and travel down the ice parallel with the 

 angular surface-moraine strewing the surface a little nearer to the 

 side. We thus have a kind of fossil moraine again playing its 

 part as a surface-moraine, at a distinctly subsequent period in the 

 glacial history of the district. 



The observations made in the previous year upon the elevation of 



^ 'Meddelelser om Greenland,' pts. i-vi (1879-1883). 

 2 Quart. Journ. Geol. Soc. vol. liv (1898) p. 205. 



