GEOLOGY 185 
Tertiary formations occur on the northwestern islands, on 
the northern part of Ellesmere, as well as on the northern and 
eastern parts of baffin island. 
The former presence of a continental ice-cap is attested along 
the northwestern shores of Hudson bay and in the southern part 
of baffin island, by the rounded and polished rock surfaces, 
which are everywhere well marked by the ice striae, often in 
several sets showing changes in the direction of the ice move- 
ment. On the east side of Baffin the rock surfaces show signs of 
rounding and smoothing by ice, but the striae are not well 
marked, and the glaciation does not appear to have been nearly 
so intense as to the south and westward. Passing northward up 
the western side of Davis strait and baffin bay the evidence of 
intense glaciation becomes less and less, that on Ellesmere the 
present condition of the local ice-covering would appear to 
represent nearly as great an amount of glaciation as ever 
occurred there. 
The sequence of earth movements and physical conditions, 
read from the geological formations of the northeast, are as 
follows : An ancient floor of crystalline rocks, largely of igneous 
origin, represents the most ancient crust of the earth. These, 
associated with ancient bedded deposits and cut by dark basic 
intrusions of trap and allied rocks, were at a very early period 
so crushed and foliated that it is now impossible to separate 
them. Upon this ancient complex was laid down a series of 
bedded deposits, chiefly sandstones and dolomites, associated 
with contemporaneous traps, as may be seen along both the 
shores of Smith sound. Following this came a great outburst 
of granite and other acidic igneous rocks which, over large 
areas, inclosed, penetrated, compressed and otherwise altered 
the sedimentary deposits to such an extent that it is now impos- 
sible to separate them from the older complex upon which they 
were originally deposited. Only in a few comparatively small 
areas were the conditions of the granite intrusion such as to 
