Denver labor bulletin., 1917-08-04
LAND OF BURIED MOUNTS.


monotonous prairie-land that lies at
the junction of the three state of Iowa,
Minnesota and South Dakota, the re-
mains of a high and mighty range of
mountains. Mr.. Charles Keyes, of
Des Moines, Iowa, who writes of the
region in the Scientific Monthly, says
that in days gone by this land was
covered by glaciers which would dwarf
existing ice fields into utter insignifi-
canoe. Lofty volcanoes poured forth
their floods of molten lava. But now
the mountains have vanished; they are
''leveled to the sea, lost and forgot
ten" Their foundations are being
slowly exhumed by the action of
stream and rain; and here and there
the old structures are being brought
to light. The traces, Mr.. keyes tells
US, are many but inconspicuous. Re-
Gently thru means of the records of
many deep well borings and other
data, the height, extent and form of
the ancient mountain range have been
fully figured and its characteristic fea-
lures pictured. Writes Mr.. Keyes:
This great earth-wrinkle which
sprang from the sea in Mesozoic times
extended from the east short of the
present Lake Superior southwestward
beyond the path of the Missouri river
Medially the rocks were bowed up
more than a mile above the existing
level of the prairies. In their prime
these Siouan mountains rivaled in see
mic beauty and grandeur the Adiron-
dacks, the southern Appalachians, or
the Juras of today. Then Jove and
Boreas and Vulcan each laid claim to
them; and each did his work of de-
molition quickly and well. They re-
duced the majestic pile of adamantine
down to the very level of the ocean,
when Neptune gathered it to his own.
"Altho now no remnant of former
mountains remains in the relief ex-
preston of the region and the entire
area of once high attitudes is as level
and smooth as any other part of the
vast interior plain, there persist be-
meath the glacial mantle mountain
structures as well pronounced and as
l typical as they are anywhere else in
the world. The broadly arched strata,
the folded formations, the faulted
rocks, the intrusions of once molten
magmas, the prodigious eXtravasa-
tions of volcanoes, are familiar fea-
lures which here are enthusiastically
developed. The evidences Of orogenic
uprisings are unmistakable. Seldom
to the geologist are mountain phen-
omena more clearly depicted. Form.
extent, and stratal attitude are meas
urable with great precision.
"The discovery of the old and long
buried mountain range Is a matter so
recent and so instructive that a brief
statement of the manner of its finding
/ is not without distinct interest It
well illustrates the method of modern
scientific venture beyond the confines
of the known. BY peeling of, as it
were. the thick Cretacic and glacial
coverings of the area the entire Mes
ozoic floor is laid bare, and the Pale
ozoic formations then constitute the
uninterrupted bed rock of the whole
region. BY what is essentially the
same thing. elimination OF these later
coverings is accomplished by plotting
the numerous deew-well records and
other data relating TO the underground
structures.
Rarely in so small compass are
there so well displayed the effects of
every great geologic process known.
For countless ages fire, flood, and
frost have played upon these rocks
without completely effacing them. Vol
canic outbursts have scanned. scared.
and smelted these formations until
often they are almost beyond recogni-
ton, but they are not yet destroyed
When rains have failed to wash these
rocks away or the rivers have been
unable to wear them down, the sea
Z has time and again cut into them or
carried them hundreds of fathoms
deep, yet they have reared themselves
again above the surface of the en-
quilting waters.
Heat of sun and chill of ice have
alternately contendei in taking off
the rock-surface: still they have ever
presented new faces TO these insidious
attempts at their destruction. Winter
blasts and the siroccan winds of sum-
mer have blown the rock areas bare
and clean as a city pavement, and the
wind blown sands and dusts have
rounded off all corners and polished all
surfaces until the hard vitreous blocks
appear as if fused in a furnace, with
out seemingly making any marked i'm
preston. Continental glaciers have
repeatedly passed over the region,
planning off the CLASSY masses as
joiner does his beam of wood. and
deeply growing the smoother facets
as by some giant graver. Compress
sion and arching of the earth's crust
have uplifted the country into noun
r IL