45 
the south of Finger Mountain. Immediately to the south of Finger Mountain the 
wedge is considerably thinner. It is exposed in the valley, which, cutting back, 
produces the sharp spur marked l\, b 2 . 
Again, on the north side of the glacier in Round Mountain (Cj) is a wedge 
of yellow rock, which is probably a similar sandstone, and is also caught up by 
the dolerite in exactly the same way. This mountain, however, differs from Finger 
Mountain in having a small sandstone-outlier which caps and protects the dolerite 
at the summit. 
Along the right bank of the Ferrar Glacier from I!, to B the sandstone may 
be seen above the level of the ice, but local disturbances prevent the upper surface 
from appearing as a continuous line along this side. 
Fig. 22 . — Fingeb Mountain. Wedge op Sandstone in the Dolekite. 
The Dry Valleys (Plate V). 
These two valleys lie on the south side of the Ferrar Glacier and on the 
west side of the Beacon Heights (B 4 , B 3 ). Both have vertical sides 500 feet high, 
which suddenly give place above to less steep slopes as the surrounding mountains 
are approached. Both are tributaries of the main valley. The smaller lies 
immediately south of Finger Mountain, and, narrowing the while, trends due west 
for a distance of two miles ; at this point the valley suddenly turns southwards, 
the ice which occupies it suddenly ends, and displays a bare, flat, stony bed. The 
confining walls continually approach each other, and one mile above the ice-cliff 
they suddenly come together in a veritable cul-de-sac. 
The larger valley is about four miles long and also ends in a cliff. Its sides 
are steep and parallel, and maintain the same height all the way round. The 
