The Saint Paul globe. (St. Paul, Minn.) 1896-1905, 1897-03-07

these stages of growth and develop
ment of this greatest mountain belt Of
the world.
Extending our view to embrace the
entire belt of which the Rocky noun
tains are a part, we see that it forms
The western side Of both North and
South America. It's length from Cape
Horn to Alaska is about 10000 miles Of
a great circle, from which the some
what irregular course Of the belt is
nowhere widely distant. With this
Andes-Cordilleran geographic belt is
also associated the mountain system,
consisting largely of volcanoes now ac-
tive, which forms the Aleutian islands,
G<amtchatka, the Kurile islands, Japan,
FOrmOsa, the Philippines, BOrneo and
Celebes, lying nearly in the same great
circle with the Andes and Rocky noun
tains, and with them continuous in an
arc of about 240 degrees. Along this
circumferential line, having an extent
of two-thirds Of the girth of our planet,
the great lateral stresses of the earth's
crust, caused by the gradual cooling
and contraction Of the interior during
long past geologic eras, and even up
to the present time, have been relieved
by plication. faults and uplifts, in the
processes of the formation of mountain
ranges.
The Gold and Sell6irk ranges of this
COrdilleran belt in British Columbia,
according to DR.. George M. Dawson,
consist of archaean, Cambrian and ST.
lurian formations, which were pushed
I'D into mountain folds before the close
of these very ancient divisions of ge-
ologic time. The auriferous states Of
the Sierra Nevada, as Becker has
shown, were similarly built up in
folded mountain range at the close of
the Gault epoch in the cretaceous
period.
Mr.. s. r. Emmons, Of the United
States geological survey from his
studies of the Rocky mountains in Col
orado, concludes that certain land
areas existed along this belt before the
Cambrian period; that mountain rang
es were thrust UP at various times
during the palaeozoic era, and in the
1urassic period near the middle of the
ensuing mesozoic era; but that these
mountains had been slowly worn away,
or reduced to very moderate heights,
before the close OF the cretaceous
period, when the mesozoic was sue
ceeded by the tertiary era.
During the later half Of cretaceous
time a vast inland or mediterranean
sea, far surprising the size Of that
which now divides Europe from Africa,
stretched from south to north across
this continent reaching from the Gulf
of Mexico over the broad area called
the great plains to the Mackenzie river
basin and the Arctic ocean. IN the
last or Laramie. division Of the Creta-
ceous period the water of this sea be-
came brackish and finally fresh, being
shut off from its former connection
with the ocean by the gradual rise Of
the land borders on the scuth and
north A great depth Of cretaceous
sediments, marine below and la ,ustrine
above, had been laid down on all the
area of the plains and upon mlch of
the country which is now traversed by
the Rocky mountain chain, bat which
had sunk in this period beneath the
sea level.
At the end of the Laramie epoch came
, great movements of uplift, folding and
overthrusting of the cretacao1s and
older strata along all the belt of the
Rocky mountains, which, with refer
ence to the date of these disturbances
Oh mountain lOrtudIlOll, mas DSSn Cdl1eQ
the laramie range The great cro-
genie movements of this time are SIM
ilarly named the laramide revolution.
For the western half of North America,
this time Of vast mountain-bui!ding
was comparable with the much earlier
Appalachian revolution in the eastern
United States, at the end Of pa'aeozoic
time, by which the Appalachian noun
tain belt was formed.
Emmons writes Of this grand stage
In the Development of The Cordilleran
mountain belt as follows: The post
cretaceous movement, as has been al
most universally recognized, was that
which produced the main plication and
faulting, and played the most impor-
tant part in determining the present
geographic features of the Rocky
mountain region. But, as it is evident
that these features had been IN great
extent already outlined IN the move
ments that went before, it is also mere
than probable that the post-creta ceous
folds and faults have been further en-
phasized along the principal lines Of