The mirror. (Stillwater, Minn.) 1894-1925, 1916-06-08
The Oldest River IN the
World

What is the oldest river in the world?
The St. Lawrence. 1t is also one of the
few rivers that did not have to make its own
bed, and has remained unchanged since
the very beginning of the American con-
| tinent.
Try to think of time when the earth
was covered by mass of water. hot, steam
ing, and often tremendously disturbed by
the throes of a globe beneath it that was
shrinking because it was becoming cooler.
As the globe shrunk, every particle of the
outside was naturally pulled in towards the
center, and the hardening crust, which
could not be packed any more solidly than
it was, had to wrinkle, sinking down here,
| and building up somewhere else. After a
time, certain of these rising wrinkles, or
folds, the thicker, or frmer, part of the
earth's crust, stood the strain, and became
permanent ridges. The oldest of them
that geologists know, and apparently the
first that bulged up above the universal
ocean and remained high and dry, was the
broad mass on which Canada now rests.
1t is part of the original crust of the
earth, and we can see it to-day, wherever
it is not covered by newer rocks or soil,
just as it crystallized and cooled out of the
primeval molten material.
This mass formed broad from La
brador down to Lake Huron, and thence
northwestward to Alaska; on account of its
shape, biologists call it the Canadian Shield.
1t is the Oldest land known, and apparently
the strongest, for there are no signs of any
extensive changes in it Except the wearing
away of the surface) since it first rolled the
| ocean off its shoulders.
Off the eastern coast of this primitive
continent lay chain of lofty islands, about
on the line of the Blue Ridge, the White
Mountains, the Main coast, and Nova
Scotia. Between these islands and the
mainland was trough-line space that ran
from eastern Quebec southwestward to
Ohio. 1t was two or three hundred miles
wide, and filled with a shallow sea; and
just outside the island chain was the great
hollow that held the Atlantic Ocean.
Time went on. For ages the straining
and cracking of the shrinking globe. earth
quakes, sun and frost, pounding surf, run
ming water, blowing gales, ice all larbor-
ed to tear down the mountains and carry
the wreckage of rocks and dust away into
the valleys and seas. In this way vast
masses of rock, in layers Of shales, sand
stone, and what not, were laid down in
that narrow trough like sea between the
chain of islands and the continent. All
these 'sedimentary' rocks were soft and
weak, as compared with the solid old
GRANTEES deeply rooted on sagging fold,
was a line of weakness in the crust. AS
the load of deposits became heavier and
heavier, the floor of this trough slowly
yielded and as it sank towards the heated
region below, the under side melted, and
grew thinner and thinner.
That could not 60 on forever, and soon
thS SOhtAhuol Vi tiiC SlOOC duQ
the enormous pressures of the weight of the
ocean became irresistible. The Canadian
Shield was immovable, so the rock in the
trough began to bulge or crumple all along
its length. Gradually, not all at once but
by slow and varying movements, those
folds were squeezed up, which in their
hrnkan and Aarrr
the Appalachian Mountains,
Towards the South there was room for
this action to be rather gentle and regular,
but in the far northeast the trough was
narrow; and the soft rocks were set on
edges, overturned and splintered against
the solid continent. Very early in the
struggle great fractures of the earth S crust
occurred here along curving northeast
and southwest line. 1t left a deep and
broad trench between the crushed and dis
placed rocks of the trough and the granite
shore of the Canadian Shield. Into this
trench rushed all the interior waters of the
continent, draining away to the sea, and
the St. Lawrence River was born There,
no doubt, it will remain as long as the
earth keeps its present form.
At that time there was no Gulf of ST.
Lawrence. The land extended out to
coast line that stretched unbroken from
Nova Scotia to Labrador. The present
gulf is the results of sinking of the coast
region Most of If is very shallow hut a
chart of soundings shows the ancient river
bed as channel winding out between
Newfoundland and Cape Breton to the
deep ocean.-Ex.