The sun. [volume] (New York [N.Y.]) 1833-1916, 1903-10-11
MINNES0TA'S OLD VOLCANOES
TREMENDOUS ERUPTIONS ONCE
IN A NOW LEVEL REGION.
Proof Discovered That the state Once Had
Great Mount aims, Though II Is a Prai-
rie n Prcsent-ENidcncesO Of the Fury
Of Its NOlcanOcs--Nlinnes sofa sink Ing.

|
Great Mount aims, Though II Is a Prai-
rie AZ Prcsent-ENidcnces Of the Fury
| Of Its NOlcanOcs-Nlinnes sofa sink Ing.
| Most of the Latives of Minnesota lave
never seen q mount ain. When they first
come Fast over the ApI alachiars tie great
hills are wonderful and Inspiring rye-
lation. Their own State has a few prctIs
of conspio uous hills ard many Bluffs alcrg
the Minnesota and some other rivers, lht
as whole the State consists OF uLGula,lg
prairie land.
Tie ordinary oil server would rever SIS.
pect. what is a fact. that the terri DRY low
occupied by Minnesota was formerly
shaken by tremendous eruptiors from vol
canoes, whose reoks or conical mounds
cannot now be even found; or that ii lad
towering mountains which have been worn
down until only their fattened stum;s
remain. But biologists tell us that he
Minnesota mountains were once high aid
| grad.
Inese facts were not discovered until
recent years, Stree the Geological Survey
| of Mime sofa was organized The scio1-
tific men Of this survey have made a very
careful study CT every part Of the State
and revealed the wonderful story OF the
ancient land
| Prof. c. W. Hall. who occupies tie chair
OF geology and mineralogy in the Uni,er-
! sity of Minnesota, tells Us in a book he las
| just written that tie volcanic phenomena
| OF minnesota were, In Their time, on a scale
more magnificent than even in Italy Hawaii
| and the Philippines, whore, as we know,
| tremendous masses of lava have been
poured out of craters to cool as basalt.
The lava streams of Vesuvius cover only
paltry few square miles; only 1900 square
miles of Hawaii are covered with volcanic
| outpourings. But in Minnesota, as Prof.
Hall relates, over 5,4OO square miles are
| 1overspread with rocks as dark in color
and as genuinely volcanic as are those OF
| Vesuvius or kilauea, and thousands Of
square miles carry more GRANTEES and other
rocks that tell the story of stupendous action
long geologic 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 recognized
in walking from the mouth of the ST. Croix
River up through the streets of Taylors
| Falls, which stands on its banks. The town
! OF Chengwatana stands on site where
at least sixty-five separate sheets of lava
may be counted.
The city of Saint Cloud on the upper Mis-.
sissippi, is surrounded by rocks that were
| fused and thrust TO the surface by tre-
mendous earth forces Along the north
west shore of Lake Superior were a series
E! of ancient volcanoes that poured out enor-
nous lava flows, built up beds of volcanic
ashes or injected molten material as broad
bikes within the older rocks
| We know that the crust OF the earth is
continually moving up and down, go slowly
that any appreciable change in level may
not be revealed for centuries. 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 sinkitg.
| The Root River, for example, seems to be
| slowly sinking about its mouth. The geoo-
| gists infer this because hundreds of acres Of
marshy land have been formed around the
mouth and along the lower part of the
river.
Having dropped to little lower level,
the river. of course, has lost impetus near
the place where it joins the Mississippi, ard
so the silt it carries has dropped within
| its own flood plain, forming the marshes
| that are gradually growing. 1t is also be-
lieved that the Mississippi River is slowly
sinking about it's head waters.
IF this prnvaS tn Ie "a fact the pn,.iOaI Io
stretches of the Mississippi above Mnne-
| apolis will become less useful, because the
! slowly flowing waters will load the bed Of
| the river with deritus and make it less
| available for transportation.
Wespeak of the Mississippi as the Father
! of Waters" but our biologists have proved
! that it's affluent. the Minnesota River, is
entitled to be called the grandfather Of
| the upper Mississippi. above the point where
the Minnesota unites with it, at Fort Smell
| ling They know that this is true because
the great valley of the Minnesota shows
| that it has been deepened and widened
| by the work of many ages, while the neigh
| boring valley Of the upper Mississippi is
n new, narrow, Clean-cut groove which has
not yet had time to dig away its banks and
| make a broad valley miles in width like
| that through which the Minnesota flows
These are only few Of the interesting
facts that have been revealed within Il 9
last few years by careful study of the
| geology Of Minnesota They show how
many interesting chapters of the past lis
tory of the surface we occupy may Ire
deciphered and made ineligible by the
methods OF modern science.
FEW EASHOISE STATESMEN.