88 GLACIOLOGY 



It was also concluded that the Solitary Rocks were not capped by Beacon Sandstone, 



but wholly formed of granite.* 



The Solitary Eocks were proved by an actual traverse to be the butt-end of a 

 peninsula banking up the ice above and forcing it round to the southern side, where 

 it descends in a series of ice-falls. 



Access was gained to the Solitary Rocks at two points. These consist of alter- 

 nate bands of black and yellow rock, which are identified on Ferrar's map as dolerite 

 and Beacon Sandstone ; but on December 22nd, on climbing down the ice-clift' and 

 crossing the frozen stream at the foot of the cliff, and climbing up the talus acree and 

 collecting from the lower yellow band of the Northern Solitary, the observer found the 

 rock to be a granite similar to that of the Kukri Hills. 



From this note about the alteration of the geological boundaries we may pass on 

 to a general description of the Ferrar Glacier. 



The entrance to the Ferrar Glacier Valley, seen above, is about 5 miles in width. 

 The facetted character of the steep walls of the valley, the entire absence of over- 

 lapping spurs, the resemblance of the whole valley to a vast, slightly curved groove "j" 

 gouged out of the plateau to a depth of fully 6000 feet, bear strong testimony to the 

 vast power of its role in the evolution of earth forms in Antarctica. 



THE FERRAR GLACIER 



The following description is based on the observations of the Western Party, 

 Armytage, Brocklehurst, and Priestley. 



The lower 10 miles of the Ferrar Glacier, below the first ice-falls, consists of ice 

 which, as far as we could judge from the surface, is not glacier ice, and it seems 

 probable that the present end of the true glacier is at those same ice-falls. 



The junction between the sea ice and the commencement of this ice is sometimes 

 a distinct cliff" several feet high, against which snow-drifts are banked, but more 

 commonly a gradual slope. It appeared, even on our outward journey, that this ice _ 

 was truly crystalline ice, due to the re-freezing of thaw-water containing large 

 quantities of half-melted snow. The surface just above the commencement of the ice 

 is, on those patches where it is free from snow, exactly comparable with that of the 

 southern half of Blue Lake, Cape Royds. The hexagonal ice is very prominent, and 

 forms in places almost spherical patches many feet in diameter, and with a convex 

 surface which is sometimes formed of beautifully regular hexagons, or, when the 

 crystallisation is less regular, of frond-like masses of crystals of all shapes, generally 



* The view that the Solitary Kocks were an isolated nimatak and were capped by Beacon 

 Sandstone was exactly the conclusion that one of us (Priestley) favoured when seeing the mass as 

 it presented itself to the sledging parties of the Discovery Expedition. It was only a closer sub- 

 sequent examination from a different view-point that proved this inference to be incorrect. 



t Nussbaum's expression, " Wie mit ein Hohleisen auf einmal ausgearbeitet," seems strictly 

 applicable to this valley. 



