DOWLIXO. 
SUTTON MILL LAKES 
23 F 
broken down and the debris has filled the channel, raising the water in 
the southern lake about five feet. The heavy mantle of drift has Koc-ksomceal- 
efiectually fioncealed the rock, and only in the river valleys and in snch ' ' 
a cat as this is much rock to be seen. The limestone of the Ek wan river 
docs not come north to the lakes, as outliers of thu trap hills occur just 
to the sooth of the lake in the valley into which the trail from the 
Washagami leads. In the northern lake, pa.st the trap hills, limestone 
again appears, and an exposure of it occurs on a small island where 
there is about ten feet exposed. Helow the water-level the cliiT is 
abrupt to a doptliof si.vty feet. This shows that probably the Silurian 
depo-sits surround the Cambrian, but are at a lower level. The valley, 
although excavated through tlie superficial deposits, found as its lowe.st 
level a former bi’eak not only through the Cambrinri at the narrows 
but also a deep cleft in the Hnie.stone beds to the north. In the valley 
which runs northward from the lake, the limestone beds cross the pre- 
sent river channel at a greater elcA atiou above the sea than the cut 
through them in th(^ lake valley. 
As to the origin of the valley in which the lake lies, it seems to be Origin of 
clearly caused by the action of a stream, which in some manner has '"‘hc-V- 
since been cliverttMl, probably to flow eastward to James bay. 
If the rising of the land was inaugurated in the southern part and 
gradually proceeded north ris the pres.sure of the glacial mass was 
removed, then the general slope nortlnvard would have been steeper 
in front of the elevated portion and drainage channels would follow in 
this direction forming valley.s trending north. After the elevation 
was accomplished or the land assumed its present contour, parts of 
tho.se valleys wouhl be so Lilted as to ba<rk up the contained streain.s 
and cause them to spill down the present slight incline t«J the east. In DifiFcrences in 
thi.s way it .seems pn>bable that such .streams as the Ekwan and Atta- 
wapiskat, which make a decided turn to the east from a point south 
of this lake, might have originally run northward to llud.son bay. In 
tho description of the Ekwan river tlie difierence in age of the upper 
and lower parts of the valley is noted and also the supposition that 
the stre.am left it.s present valley near the mouth of the Little Ekwan. 
The great depth.lo which the b»win is eroded may be due to other 
causes, and one suggested by the presence of faults at the narrows is 
that the changes of level to which tho crust has l)ccn subjected caused 
a groat fi.ssuro to open along the line (5T the lake vallc}* and a portion 
of the overlying deposits wa.s thu.s alloweil to drop down If however, 
this was the chief cause, the break would probably be traced for a 
greater distance than the length of the present lake valley. 
