BY GRAHAM OFFICER, B.SC. 153 
that they do on the other. This is indicated by the 
numerous, and often very large, blocks of sandstone and con- 
glomerate that occur mingled with masses of greenstone 
towards the upper end of the Cuvier Valley. At one place, 
just below the southern extremity of Lake Petrarch, these 
masses of rock form a ridge reaching nearly half-way across 
the valley. A large boulder of conglomerate can be seen on 
the S.W. shore of Lake Petrarch, which has evidently fallen 
from the heights above. The shores of Lake Petrarch are 
sandy and gravelly, such as would result from the disintegra- 
tion of sandstone and conglomerate. 
The summit of Mount Olympus is much like that of Mount 
Wellington, a rough, uneven plateau-like surface, formed by 
the unequal weathering of the greenstone columns, some of 
which stand up like sentinels among their fellows ; many of 
them are 15 feet or more in diameter. A, noticeable feature 
is the presence of several large fissures, which gape across the 
mountain in an east and west direction approximately. The 
largest of these fissures had a great deal of snow lying in it, 
so that we could not see the depth; 50 or 60 feet would be 
somewhere near it. These fissures are being filled up by the 
falling columns. As to their origin I do not care to speak 
definitely. Perhaps they are due to dislocations, perhaps to 
the undermining action of water in wearing away the under- 
lying rock. 
From Olympus it is seen that the Traveller Range on the 
opposite side of the lake is really the edge of a piateau 
stretching away for miles beyond. This plateau is of green- 
stone, and its roughly undulating surface is studded over 
with lakes and tarns of all sizes, recalling the Scottish High- 
lands again. The Traveller Range preserves an even, slightly 
undulating summit till it is terminated by the deep valley 
that separates it from Mount Ida. The structure of Mount 
Ida is a repetition of that of Olympus, a crest of greenstone 
with horizontally bedded sandstone below. We did not 
reach the top of Ida, but went about half-way up from the 
lake side. A stream that flows down between Mount Ida and 
the ranges to the north we followod. up for some distance 
and found that we were on sandstone all the way. From 
Lake Daura, lying beneath Mount Ida, and slightly to the 
N.W., a splendid view of the mountain is obtained, the 
horizontal beds of sandstone being clearly seen at about two- 
thirds of the way up the mountain, while the sharp peak of 
columnar greenstone stands out clearly against the sky, 
The Eldon Range, to the N.W. of Olympus, according to the 
geological map, presents the same appearance as Olympus 
and Ida, viz.,a greenstone centre or crest, with a base of 
sandstone. 
The appearances I have described seem to me to point 
K 
