Baraboo weekly news. [volume] (Baraboo, Wis.) 1912-197?, 1912-08-08

ness OF seven or eight thousand feet,
the sea bottom was elevated and be-
came dry land. Tue region was up
lifted into a mountainous tract, the
once horizontal strata were uptilted
and folded together like the mountain
mountain ranges as the Rocky and the
Allegh Aney ranges. The strata here at
the lake are tilted at an angle of Is to
20 degrees, while in many other places
on the quartzite ranges the beds star
up in vertical position. During this
process of mountain making the rocks
were subjected TO great heat and pres
sure, the sandstone was changed to
hard quartzite, the shale to slate and
the limestone TO marble.
The mountain ranges of that time,
just as they are today, were exposed 10
the winds, rains, frosts and SHOWS,
and by these agents, and especially
by running water, they were largely
worn away just as all existing noun
tain ranges are being worn away. The
process of wearing away continued so
long that finally only fragments of the
original mountain folds remained.
These fragments are the quartzite
ridges which on account of their hard
ness as compared with the slate and
fOr iov <.yithcfnnA
the process of wearing better and
hence, after the long period of erosion,
the quartzite stood out as low noun
tain ridges above the surrounding
plain of softer rock. These quartzite
ridges stood in the final stages of the
of the mountain ranges, at
an elevation of only 1000 to 1880 feet
above the surrounding plains. The
quartzite ranges were therefore low
ridges in the ancient plain
and though of relatively low elevation,
they were the highest peaks over an
extended area In what is now the
upper Mississippi valley, the central
portion of the continent. Such a
mountain as this, worn down by ero-
sion from a greater mountain range,
is known as monadnock, named
after Mt. Monadnock in New Hamp-
shire, which bears similar relation
to the plain associated with the AL
mountain range.
Beginning of Life ON the Earth.
The next chapter in the recorded
history deals with the gradual sub
of the region beneath the sea
10 what is know As the Cambrian per-
lod, which is the earliest of the PaIeo- |
zOic era, and bears records of the very
early beginnings of life on the earth.
AS the waters of The Cambrian sea |
crept in about the quarlzite mountains,
sand and gravel were laid down upon |
the shallow sea bottom. The sands |
and gravel beds are still in horizontal |
position on the slopes OF the ranges |
and in the surrounding valleys. The |
water in which these formations were |
deposited is known to have been the !
sea, for the shells of animals in
,he sands now cemented to sand
stone, are the shells of marine
animals, and many ripple marks made
~ the waves of the sea may be seen in
he sandstone beds.
The early Cambrian sea was present
or very long time during which the
Iuartzite ridges were slowly buried by
he gathering of sands about their
,sses. 1t seems certain that in time
hey were completely buried, and dis
appeared entirely as surface features.
The depth to which they were buried
5 not known but it seems Likely that
most of the geologic formation of
lmestones and shale of eastern and
western Wisconsin extended over this
ocality.
Finally the waters of the sea with
rev, probably because the ocean
asin elsewhere sank enough to draw
fl the shallow waters which for
econd time had spread themselves
yer this part Of the land. The for
nations laid down in the sea, when
was present, were exposed to
rosion when it withdrew. AS in the {
arlier period of the erosion of the :
FOUNTAINS, various agents co.operated
/ wearing away the surface rock, but
mong them running water was the
lost important. This period of
-osion was of great duration and as
! the former period of erosion, must
e measured in millions of years. ::
curing this period of erosion, the :
,gion was not elevated and folded in r
, a high mountain range, but was
lerely uplifted into broad plain or
evated plateau, for the sandstone and
of this period are still in
orizontal position as they were
hen originally deposited. During
lis period of low uplift and erosion
much of the sedimentary rock de-