Vermont phÅ“nix. [volume] (Brattleboro, Vt.) 1834-1955, 1892-05-20

necessary to afford an explanation for the
origin of our rocks, our mountains, and
our valleys. That they are not today what
they were Yesterday, and will be something
else tomorrow, is beyond the possibility of
a doubt.
Before | leave this portion Of my sub
ject ! want to say a word in regard to
mountain building. We have seen now,
little by little, the mountains are cut away
by the streams, and how slowly, after all,
the deposits must have accumulated on
the sea floor to form the thousands of feet
of strata that are exposed in the noun
famous regions Of the globe. But after
accumulation has ceased and the deposits
are raised above the level of the water,
long ages must elapse before they can be
np-folded into mountain chains. Such re-
suits are not accomplished in a day. The
older biologists, however, thought that at
certain periods in the earth's history great
commissions had taken place; that some
cataclysm, destroying the relations Of land
and sea and discriminating all forms of
life, had occurred. A more careful exam
inatiOn Of all the facts presented to us
shows no evidence for any unusual exhibit
tons of natural force. The cumulative
result of those agencies, which are acting
The earth we believe to have been slow
ly cooling down from first a gaseous, then
a molten mass. After the solid crust
formed, the highly heated interior still ra-
dated heat, and as it did 50 occupied less
and less space. A bar of iron is longer
when hot than when cool. As the interior
contracted, the solid crust, in conforming
thereto, was crumpled and folded in much
the same way the skin Of an apple folds
when the interior dries. These folds,
which we call mountains, that were slowly
formed and are forming today, were at
tackled by the streams from the first so
that they must have lost continually from
their higher points as the process of de-
velOpmcnt went on. The constructive
forces must have acted more powerfully
than the destructive, however. or else the
mountains, themselves, would never have
been produced. As the folding went on,
the rocks were also here and there disrupt
ed, the results of which are manifested in
great dislocatiOns in which the strata are
pushed at times thousands of feet out of
their normal position. At the time these
earth movements take place jars occur that
We call earthquakes.
There is line of assure in the earths
crust passing down the Hudson valley
through New York, Philadelphia, Balti-
more, Washington. Richmond, and reach
ing to Charleston, where in time gone past
the strata have been disrupted for a dis
lance of hundreds of feet. 4 slight move
ment took place at the Charleston end in
1856 with disastrous results. When there
may be violent movement along the re-
mainder of the line it is impossible to pre-
d ct, but it is hoped that it may be long de-
ferred. In Vermont we are seldom troubled
by earthquake shocks that have their CEN
tres i'm our midst. The explanation for
this may be found in the fact that the
Green mountains were formed long ago,
and we have no evidence that movement is
now in progress. The Green mountains,
in fact, are older than all the other noun
tain ranges on the continent so far as
we know. The Alleghanes, the Blue
Ridge. the Rockies, the Sierra Nevadas,
the Coast range were all formed AT much
later date. ] think most of us are quite
well satisfied that the Green mountains are
not growing any higher. In all else we
welcome growth, but in the case of the
hills we can rest content to let the process
of erosion 90 on without a protest.
| have spoken thus far of those agencies
that are active today, and Of which our
own region furnishes us excellent illustra-
tions. Let us turn for few moments to
some other changes of which the results
alone are shown, the forces that produced
them having long since ceased in our
midst. Although not the oldest of the ge-
illogical phenomena presented to'Our view,
having been active long after the noun
tains had been folded and the valleys for
the most part carved, when in fact the to-
wi,
the present, they are yet so old that many
traces of their occurrence have been oblit-
Grated. | refer to the changes produced
during the glacial period. Intense cold
prevailed at that time over the northern
portions of North America and Europe.
Great fields Of ice, similar TO those now
seen in Greenland and other regions of the
North, extended far within the limits Of
the United States. This ice mass moved,
as the Arctic ice moves. today, slowly but
surely onward.
If you place a mass of hardened pitch up
on a level surface it will slowly spread out
ward from the centre, and if the mass is in
creased by additions at the central point, the
pitch will flow farther and farther until, fl
nally, it will spread to a great distance. So
it is with great ice masses. During the
glacial period, the central point of move
ment was to the east of Hudson bay, and
from there the ice spread eastward over
Labrador and eastern Canada, southwark
over New England, south westward over
the states of the Northwest, and westward,
and even north-westward over the western
provinces of British America and Alaska
The precipitated moisture, in the form of
snow, must have accumulated to great
depths, for we find that the ice reached a
thickness of over 5000 feet in northern
New England, and thence gradually thin
ned down to its southern border which
extended from Martha's Vineyard across
Long Island, northern New Jersey, Penn
sylvania, Ohio, Indiana, Illinois, and
thence north-westward through Dako-
ia to the British provinces. The area
to the north of this line, including our own
region, was entirely buried by this great
ice sheet.
You may perhaps ask, how do we know
that such was the case, when neither our
own observation nor history afford us any
evidence of its existence. In high noun
famous areas, and in the Arctic regions,
we may today study the effect of ice upon
the land over which it flows. We find that
the surface is scored and that the loosened
debris is borne from one point to another
If we examine the surface of our own re-
gion we find many evidences of this action.
The rocks have been rounded and polished