214 R. W. ELLS—SANDS AND CLAYS OF THE OTTAWA. BASIN. 
ties of Addington and Hastings, is, however, occupied by the Archean, 
and this produces, over a considerable area, some of the roughest surface 
in eastern Canada. The streams which flow thence into the Ottawa are 
not so large as those in the northern portion of the basin, but are still of 
good size, and comprise the Petewawa, Madawaska, Mattawa, Bonnechére, 
Mississippi, Rideau, and South Nation. 
To the north of the Ottawa the principal streams east of the Gatineau 
are the Lievre, North Nation, Rouge, and North. These all head in the 
Archean highlands, and traverse the crystalline rocks to within a short 
distance of their junction with the Ottawa. Of these the Lievre is the 
longest, and has its source near the headwaters of the Gatineau and Saint . 
Maurice. 
GENERAL CHARACTER AND DISTRIBUTION OF THE CLAY D&rposits 
Over much of this large area, both to the north and south of the Ottawa, 
deposits of clay are found. This clay is usually of the blue variety, sim- 
ilar in character to much of that which occupies the valley of the lower 
Saint Lawrence. It is found on all the streams, frequently underlying 
great areas of sand and gravel, as far as the height-of-land in the north 
part of the basin, so that it is evident these deposits are very widespread. 
They are frequently well stratified, layers of sand and fine gravel alter- 
nating with the clay in the upper part of the latter, but the lower por- 
tion of these deposits is almost entirely a firm blue clay. Along the 
line of the Ottawa and Parry Sound railway these clays are seen as far 
west as Barrys bay, which is on the upper waters of the Madawaska, un- 
derlying the sands at an elevation of over 900 feet above sea, the elevation 
of Barrys bay station being 987 feet. 
Along some of the rivers, as the Gatineau, the extent and thickness of 
these clay deposits are very great. On the line of the Gatineau Valley 
railway there are cuttings in the first 50 miles north of the Ottawa in 
this material fully 100 feet deep, overlaid with sands at a number of 
points, while on the Bonnechére, in the flat area west of Renfrew, the 
thickness, judging from the sections along the river courses, must be 
equally as great. . 
GENERAL CHARACTER AND DISTRIBUTION OF THE SANDS 
The overlying sands are well seen along the streams on both sides of 
the Ottawa river, and they form a widespread mantle extending beyond 
the height-of-land. They are usually fine grained and in places, as along 
the river above Pembroke, they have a thickness presumably at least 
of 100 feet. They not only occur at these high elevations, but are also 
