The Barre daily times. (Barre, Vt.) 1897-1959, 1915-10-18
WHEN AMERICA WAS YOUNG.
Vast Shallow Inland Sea and Swamps
Where Rocky Mountains Now Stand.

The United States Geological Survey
has just published a report which
though technical, nevertheless embodies
some interesting history of the early
ages of the North American continent
It tells of the rise and fall of a portion
of the continent millions Of years ago,
long before the age of man, at q time
when strange beasts inhabited the coun-
try, when the climate was subtropical,
and when peculiar swamp vegetation
hourished, the remains of which were
converted into the present great coal
beds of the West.
Late in what is termed by biologists
''Carboniferous time" according to w.
T. Lee, the author of the report PRO
fessional paper 95-C), there were noun
tains in Colorado and New Mexico com
parable to the present Rocky mountains.
During the Triassic period and much
of the Jurassic, which followed, time
to be measured in millions of years,
these mountains were eroded away. Late
in the Jurassic period wide area had
been worn down so near sea level that
a slight subsistence of the land allowed
sea water to enter from the Pacific ocean
and spread over Wyoming, northern Col
orado and eastern Utah. Near the close
of the Jurassic slight uplift expelled
this sea. After some time this area
began again TO settle and the streams
spread fine sediments over the bed Of
the shallow basin lately occupied by the
sea and over the low lying lands. This
subsistence introduced the Cretaceous Pc
riod and eliminated in the occupation
of the region by a sea which reached
from Utah to the Mississippi valley and
from the Gulf OF Mexico TO the Arctic
ocean.
The subsistence was slow at first and
the streams spread their muds uniform
ly over an area extending from New
Mexico to Montana and from Utah 10
Kansas. Only small areas of the Rocky
mountain region were not covered by
them. In the streams, swamps and bay
Gus of this cary Cretaeeous time lived
huge reptiles; some of them were 50
feet long and % feet tall, with bulk
many times as great as the largest ele
plant OF to-day. BY the close Of Lower
Cretaceous time the water from the Gulf
of Mexico had spread over the graded
plain as far as the present Rocky noun
tains. This invasion of the sea was fol.
lowed, apparently without great lapse
of time, by a still greater invasion in
the Upper Cretaceous epoch.
The first deposits of Upper Cretaceous
age-the Dakota sandstone--were spread
out uniformly over the level plain, which
then included the whole area that was
later pushed up TO form the Rocky
mountains. over these sands, which
were laid down along the advancing
front of the sea, were deposited the
marine sediments as the sea moved for
ward. In its waters lived great numbers
Of serpent like swimming reptiles, and
over il scared petrodactyls, the fossil
remains Of which show that they meas
ured Is feet from tip TO tip Of wings.
On its shores and in its waters sported
large diving birds. which still retained
the teeth inherited from their reptilisn
ancestors.
On the shores Of this sea. especially
along its western margin, great swamps
developed and in them grew a variety OF
semi-tropical plants. such ~ palm and
fg trees The result carbonaceous ma 1
terial which accumulated az peat was
later converted into coal The sea did /
not attain its maximum sire at once. I
Probably AZ no one time was the whole 1
interior basin under water. The advance I
81 the sea and the filling Of the basin I
<ept pace with each other. 30 that sedi- I
nents and fossils which indicate near
ness 20 shore and coal beds which Incl /
ate sWamps above sea level are found /
u many positions from bottom 10 top
II the Upper Cretaceous formations.
At the close Of the Cretaceous period I
notable changes were produced in the
geography Of the region. The interior
assn, which had been subsiding through
lut the Cretaceous period. vas nov lift
d IL waters were poured back into TIE
,ceans, and the mountains whose roots
iad bepa buried were resuscitated. IN
Iome places the erosion that followed
emoved from these newly lifted noun
aims the Cretaceons rocks that once
overed them and cut deep enough into
De underlying Formations 20 obtain the
,ehlsles Of older rocks. which NAV rev
= found in tire lower part Of tire oldest
Tertiary beis. IN other pisoes the Gre
ace0us rookie were not entirely removed.
Beds that once lay s069 feet below the
eFel 81 the sea were lifted e. form
mountain tops that u8E stand uore
Ran % N0 fest above sea lo=nl