102 ROYAL SOCIETY OF CANADA 
The outlining of the exact boundaries of the several divisions of 
the Palæozoic fossiliferous rocks in this area is not easily effected. 
Over much of the country, there are wide-spread areas of drift, some- 
times in the form of sand, but often occurring as ridges of boulders, 
largely made up of transported material, for the most part derived from 
the great mass of the crystalline rocks north of the Ottawa river, the 
general tendency of the later drift having apparently been from the 
north-east to the south-west. The evidences of ice movement in this 
district, however, tend to show that such movements varied greatly at 
different times; so that there would appear, from the courses of the 
glacial striæ which are fairly numerous over a large area, to be no less 
than three such periods. Of these presumably the first movement of 
the ice was in a generally south-east direction from the high lands north 
of the St. Lawrence into the valley of that river. The traces of this 
south-easterly movement are well seen along the course of the Ottawa, 
the general direction of which it has very closely followed. A second 
series of striæ which are widespread, was apparently from the north and 
north-east to the south and south-west, following the general course 
of the St. Lawrence upward towards the great lakes; while a third set 
of markings occurs along the lower Ottawa and at many points to the 
west and south, some of which have a nearly east and west direction. 
These would appear to owe their origin to great masses of floating ice 
which moved up the St. Lawrence and over a large part of eastern On- 
tario, during the period of submergence subsequent to the date of the 
second glaciation. Long lists of these striæ have been prepared for the 
area adjacent to the St. Lawrence and the Ottawa rivers, some of which 
have been published in a recent report on the district by Mr. R. Chal- 
mers, where these have been classified according to that writer’s views 
as to the course of the several ice-movements. 
The geology of the area between the Ottawa and the St. Lawrence 
has now been carefully studied as the result of several years’ work in 
the field. The information thus obtained has to some extent been sup- 
plemented by the records of various borings which have been made at 
different times, at widely separated points, and these have lately been 
carefully compiled. Concerning these borings it must be said that in 
some cases the logs of several wells have been too imperfectly kept to be 
of much value. 
The thicknesses of the several formations in the principal basin 
have been to some extent determined, but these presumably vary con- 
siderably at different points. The presence of a number of faults which 
traverse portions of the area, tends to complicate this problem, and these | 

