The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1885-1921, 1903-11-01
MlNNESOTA'S OLD VOLCANOES
tremendous Eruptions Once in Now Level
Region.

| Most OF the natives of Minnesota
have never seen a mountain. When
they first come East over the Appala-
chan the great hills are a wonderful
and inspiring revelation. Their own
State has a few groups of conspicu-
Gus hills and many bluffs along the
Minnesota ana some other rivers, but
as whole the State consists of I'M
dulating prairie land.
The ordinary observer would never
suspect, what is fact that the terri
/ tory now occupied by Minnesota was
formerly shaken by tremendous erup-
| lions from volcanoes, whose necks or
confcal mounds cannot now be even
found; or that it had towering noun
| tains which have been worn down un-
Til only their fatrened stumps remain.
But biologists tell us that the Mime
sofa mountains were once high and
grand.
These facts were not discovered UNI
ii recent years. sir ce the Geological
Survey of Minnesota was organized.
The scientific men of this survey have
made a very careful study of every
part of the State and revealed the
wonderful story OF the ancient land.
Prof. c. w. Hall. who occupies the
chair of geology and mineralogy in
the University of Minnesota, tells us
in a book he has just written that
the volcanic phenomena of Minnesota
were, in their time, on scale more
ma rVpi no ~ Ii
wall and the Philippines, where, as
we know, tremendous masses of lava
have been poured out of craters to cool
as basalt. The lava streams of Vesu-
vius cover only d paltry few square
miles; only 1000 square miles of Ha-
wall are covered with volcano out
pourings But in Minnesota, as Prof.
Hall relates. over 5,400 square miles
are "overspread with rocks as dark
in color and as genuinely volcanic as
are those of Pesuvius or Kilauea, and
thousands of square miles carry more
GRANTEES and other rocks that tell the
story Of stupendous action long geo.
logic ages ago
The region of Minnesota has many
times been shaken by volcanoes. Four
periods of eruptive activity may be
counted in the rocks as one walks
the streets Of Duluth.
Six or seven lava flows are recog-
nized in walking from the mouth of
the St. Croix River up through the
streets 90 Taylors Falls, which stands
on its banks. The town of Chengwa-
tana stands on a site where at least
sixty-five separate sheets of lava may
be counted.
The city of Saint Cloud, on the up
rocks that were fused and thrust
to the surface by tremendous earth
forces. Along the northwest shore CT
Lake Superior were series of ancient
volcanoes that poured out enormous
lava flows, built up beds of volcanic
ashes. or injected molten material as
broad bikes within the Older rocks.
We knewsthat the crust of the earth
is continually moving UP and down.
so slowly that any appreciate change
in level may not be revealed for CEN
turtles. These changes of level may
best be observed along the margins
of the sea, and we know that part
of our Atlantic coast is now very
gradually sinking, while parts of the
Scandinavian coast are rising.
The Minnesota biologists tell us that
parts of the State are gradually sink
ing. The Root River, for example,
seems to be slowly sinking about it's
mouth. The biologists infer this be-
cause hundreds of acres of marshy
land have been formed around the
mouth and along the lower part of
the river.
Having dropped to a little lower
level, the river. of course, has lost i'm
petus near the place where it joins
the Mississippi, and SO the silt it car
ries has dropped within it's own flood
plain, forming the marshes that ara
gradually growing. 1t is also believed
that the Mississippi River is slowly
sinking about it's head waters.
If this proves to he fact the navi-
gable stretches of the Mississippi
above Minneapolis will become less
useful, because the slowly flowing wa