The Washington times., 1901-07-14
CHICAGO TO BE SUBMERGED
GeOIOgi,ts Say Lake Nj ;higan Will
Sweep Over the City.

From cszuS that are uIlilllS "a afAeolS'
IT has been determined by geologists
that the Eastern portion OF the United
States is rising above the sea level at
about from TO in hes every hundred
years. This uplifting process has, 1t
is claimed. been going on for a long
time. As a result, the Great Lakes
have more than doubled their original
area and the waters of Lake Michigan
will the scientists declare, ultimately
submerge Chicago and empty them
selves into the Illinois and Mississippi
rivers. instead of into Niagara and the
St. Lawrence, as at present.
C. w. Gilbert. one of the best known
geologists Of this country, says that
the history of the Great Lakes prac-
ticaIly begins with the melting Of the
great ice sheet that spread over a vast
portion of the North American cent?
nent ages ago. the thickness OF which
in some places was as much as four or
fye miles. The ice came from the north
and northeast, and spreading over the
country, invading the drainage districts
of the Mississippi, Ohio, Susquehanna,
and Hudson. During its wanderings
there was a long period when the
waters were ponded between the ice
front and the uplands south of the
Laurentian (St. Lawrence) basin,
forming a series Of glacial lakes, whose
outlets were southwark through various
low passes a great stream from The
Erie Basin crossed the divide at Tort
Wavne to the Wabash River. A river
1F Ter
ward flowed from the Michigan Basin
across the divide at Chicago to the II
Iinois River, and still later the chief
outlet was from the Ontario Basin
across the divide at Rome to the Mo
hawk Valley.
The positions Of the glacial lakes are
marked by shore lines, consisting Of
terraces. cliffs. and ridges, the strands
and spits formed by their waves. Sew
eraI OF these shore lines have been
traced for hundreds of miles, and
wherever they are thoroughly studied
il is found that the- 10 longer lie level
but have gentle slopes toward - south
and southwest Formed at the edges
OF water surfaces, they must original
ly have been level, il is claimed, and
their present lack of horiZOntalty is
dre to the unequal uplift Of the land.
The region has been tilted TO the south
southwest
TIE FORMATION or LAKE ERIE.
The epoch Of glacial lakes, or lakes
partly bounded by ice, ended with the
disappearance of the ice field, and there
remained only lakes Of the modern type,
wholly surrounded By land. These were
formed one at time, and the first to
appear was in the Erie Basin. That is
Lake Erie. It was much smaller than
the modern lake, because the Lasin
was comparatively low at the north
east. Instead Of reaching from Buffalo
10 Toledo, II extended only 10 a point
opposite the present city Of Erie, and
il was but One-sixth as large as the
modern lake Since that time the land
has gradually risen at the north, can't
iTg the basin TO the south, and the lake
has gradually eHcroached upon the low
lands Of the valley.
The next great lake TO be released
from the domination Of the ice was
probably Ontario. Before the Ontario
Valley held q land-bound lake it was
occupied by a gulf OF the ocean. In the
extreme northeast, in the vicinity of
the Thousand Islands, the marine
shores are nearly 200 feet above the
present water level. but they descend
southwark and westward, passing be-
meath the lake level near Oswego, and
toward the western end of the lake
must be submerged several hundred
feet. This. condition was Of short dura-
tion. and the rising land soon divided
the waters. establishing Lake Ontario
as an independent water body.
LAKES FORMERLY A GREAT GULF.
There is reason 10 think that the up
per lakes, Huron, Michigan, and Su-
perior, were first open to tbe sea, so
as TO constitute a gulf. but the evidence
is not as fun as could be desired. When
the conditions were such as to turn this
gulf into j lake there was but a single
lake instead Of three separate bodies
Of water as at the present time, and the
outlet instead Of being southwark
from Lake Huron, was northeastward
from Georgia Bay, the outlet river fol-
lowing the valleys Of the Mattana and
Ottawa TO the St Lawrence.
The triple lake line, called the Nipis-
sing shore line is not wholly sub
merged, like the cid shores Of Lakes
Erie and Ontario, but lies chiefly above
the present water surfaces. It has been
observed at many points about Lake
Superior and the northern parts Of
Lakes Huron and Michigan. and meas
urements of its height show that its
plane has a remarkably uniform dip, at
: inches Per mile, in a southwest diTec-
tiOn.
The southwark fitting of the land. in
volving the uplift of the poin, Of out
let at Georgian Bay. increased the ca
pacity Of the basin and the volume of
the lake, gradually carrying the coast
line southwark in Lake Huron and Lake
Michigan. until. finally, 1t reached the
low pass at Port Huron, and the water
oyerhowed via the st. Clair and De
trOit channels TO Lake Erie. The out
let by the way Of Ottawa was then
abandoned, and a continuance OF the
uplift caused the water 10 slowly re-
cede from its northern shores. This
change, after a time, separated Lake
Superior fr0ra the other lakes, bringing
the ST. Aary's River into existence, and
eventually the present condition was