[TYRRELL] PRESIDENTIAL ADDRESS 15 
Fox river is 180 yards wide at its mouth, but its banks have not 
yet been examined, while Hill river, which joins it from the south, 
and down which we travelled, is only 95 yards wide at its mouth. 
In ascending Hill river the banks for about 12 miles are 60—80 
feet high, being composed of till overlain by stratified sands. Above 
this they rise within a few miles to heights of 180 feet, where they are 
composed entirely of till, and from there upwards to The Rock they 
are high, and though they were not closely examined, they seemed 
to be composed entirely of till. The valley itself is very new, being 
still in the stage of active downward erosion. The banks are steep, 
and there are no flood plains, except at the mouths of small tributary 
brooks, none of which cut through the little flood plains, but flow 
into the river over them. 
Now returning to the mouth of Shamattawa river and follow- 
ing it upwards, the banks are at first of till overlain by stratified 
sand and gravel, but farther up stream they rise to heights of 170 feet, 
and are composed of till, on top of which is an old gravel beach with 
an elevation of about 300 feet above the sea. When well exposed 
in scarped cliffs this till is seen to be divided into an upper and lower 
portion by a horizontal line which is usually from 30 to 50 feet above 
the bottom of the cliff, or at an elevation of 130-150 feet above sea 
level. A similar subdivision occurs in the till on Severn river. 
In this dividing line or plane there is often a layer of coarse interglacial 
sand and gravel from an inch or so to two feet or more in thickness. 
In the sand, and occasionally in the till for two or three feet above it, are 
fragments of wood, and pieces of moss slightly darkened in colour, 
clearly indicating shore or very shallow water condition at the time 
of deposition of this sand. The presence of the wood in the bottom 
of the upper till, and of the sand beneath it, would also indicate that 
while the glacier incorporated into its till some of the wood which had 
been in the sand, it had not sufficient power to crush or remove all 
the sand. It is also evident that, as stated on page 16, this old inter- 
glacial land surface was about 300 feet or more below the level to which 
the water of Hudson Bay rose in later glacial or post-glacial times. 
At Limestone Rapids, a little farther up Shamattawa river, 
the till overlying the limestone decreased to a thickness of about 
30 feet, apparently entirely the lower till. 
This was as far as it was possible for me to examine this interesting 
river. 
On Machichi river, which flows into Hudson Bay a short distance 
east of Hayes river, cliffs of till up to 60 feet in height bound the valley, 
while the newer marine sands and clays are conspicuously scanty. 
