
GLACIAL PHENOMENA AND SUPERFICIAL DEPOSITS. 217 
sary agent by some geologists—or the Laurentian axis was occupied at 
one time by a great confluent glacier, pressed outward mainly by its own 
weight and mass, and directed only, by the pre-existing inclination. 
Having met with no evidence of the former, I prefer to account for the 
facts on the latter hypothesis, which will receive more extended notice on 
a subsequent page. 
493. The general contour of the country surrounding the Lake of 
the Woods, and its position with regard to the watershed, and axis of 
Laurentian elevation, seem to show that the direction of drainage has not 
always been as at present. The initial cause of the Lake of the 
Woods basin, has no doubt been the occurrence of an area of softer 
Huronian rocks, among the Laurentian; and the rocky surface as 
already shown, sinks gradually but persistently away to the southward 
and westward, and in that direction, soon becomes buried under a 
vast accumulation of drift and alluvial deposits. It is probable from the 
conformation of the country, that were the drift deposits now blocking up 
the southern part of the lake removed, its waters would flow southward, 
in conformity with its general, primary inclination. The watershed 
between the lake and the Red River Valley, lies close to the former, and 
has an average height of perhaps not over thirty feet, the summit being 
occupied by great muskegs. Sections were seen on the Kast Roseau River, 
not twenty miles west of the southern part of the lake, which showed 
nothing but sand and detrital matter, to far belew the level of its waters. 
Supposing then the absence of this drift material, the small streams now 
running into the northern part of the lake, would flow southward, along 
the belt of softer Huronian rocks, forming a valley; and toward the south- 
ern part of the region now occupied by the lake, must have joined the 
larger stream of Rainy River, and then flowed south-westward through 
the northern part of Minnesota, toward the valley of the Red River, 
which—as elsewhere stated,—may very probably at this time have passed 
southward into the representative of the Mississippi of to-day. 
494. During the glacial subsidence, the great deposits of sand and 
clay were formed, blocking up the entire southern part of the lake, and 
producing the low watershed to the west; through Clear-water Lake, as it 
formed a bay in the Laurentian, and from its rocky and tortuous outline, 
may probably have escaped the action of the currents bearing silt and 
debris. On the emergence of the country, the waters of the Rainy 
River being dammed back from the south, would probably creep round 
the junction of the metamorphic rocks and drift deposits, to Clear-water 
