Delaware gazette and state journal. (Wilmington, Del.) 1883-1902, 1894-10-11


structive article from the pen of Profess
sor Thomas Chamberlain, head of the
Department OF Geology of the Univor.
sity of Chicago, who accompanied Lieu
tenant Peary's last expedition TO the far
North, will appear shortly in the
journal of Geology"
The study Of Greenland glaciers, says
the professor, has specific bearing
upon one of the most widespread and
important of our geological formations,
The larger portion OF sixteen OF the
northern States and smaller portions of
eight or ten others are covered by a
mantle Of clay, sand and gravel, filled
with powders transported from the
North. This mantle forms the subsoil
of about one.third of the cultivated nor,
ton of the United States, and very
large part of its fertility is dependent
upon this. The spreading Of this mantle
over these States very much suhdued
the topography and thereby rendered
tho construction of railway lines and
other means Of transportation easy and
economical where they would otherwise
have been difficult and expensive, and
in some cases impracticable. Many lines
owe their existence to the smoothing
down of the surface brought about by
this formation.
The explanation Of this deposit, which
Is known as the drift, has been one of
the most difficult problems of geology,
and probably more has been written
upon IL than upon any other single
topic In the whole range Of science. 1t
was formerly attributed to great floods
sweeping down from the North
T,otar n una pTiita franorol1,F rafnrrnI
icebergs floating over the region during
state Of submergence. 1t is now gener-
ally attributed to glaciers that are be-
lieved to have covered nearly one.half
of North America, reaching southwark
as far as New York, Cincinnati, St.
Louis and Kansas City. 1t is only in
Greenland and the Antarctic regions
that glaciers of such vast dimensions and
of like modes of action are now found,
and, of these. Greenland offers the only
accessible field of investigation. Hence
the importance of studying its glaciers
as means of calculation Of one of our
most important and interesting geologl.
cal formations.
Evidences of like action are found in
both countries. For instance, glaciers in
moving over the surface rub away tho
along with them more or less of the
rock below, and in doing this they score
and groove and polish the underlying
rock surface in q way altogether pecu.
liar to themselves. They thus engrave
their own record-their autobiography,
so TO speak--and we have only to deci-
pher their language to read their his
tory. The material TINT is carried along
Ia nj
scratched, and mora or less ground to
powder, and when the action ceases this
material Is spread out upon the surface
or heaped up into ridges alone. All
these characteristics are abundantly dis
played in both countries, and it is quito
clear that the work that is now being
done by the glaciers of Greenland is of
the same nature as that formerly done
upon large part of our own country
This implies great changes In our of
mate. The climate of Greenland prob
ably formerly prevailed over our north
ern States. Giaciation is, however, very
strange phenomenon, and we do not yet
know all its mysteries nor the full range
of conditions that render it possible. |
examined fourteen glaciers In the north
ern district, and three on Disco Island
of three or four score others, but can
hardly be said to have examined them.
1t should be understood that nearly all
these are tongues, or lobes, of the great
inland icecap Vt Greenland, or of local
tcecaps, and that the study OF these ice
caps was an important part of my work,
visited tho inland Ice and had the
good fortune to have the guidance of
Lieutenant Peary in a strip upon the
main icacap, in which we went sutfic-
iently far to get typical view of the
great fields of the interior. My studies
were, however, chiefly on Its margin, as
it was most important to me to ascertain
what was the nature OF the base of the
ice, and its methods of erosion, trans
portation and deposition. The glaciers
of the Alps, and of mountains gener-
ally, are chiefly formed from SHOWS ac-
cumulated on the upper slopes in lofty
amphitheaters or in the rayines or
gulches that crease their peaks. These
creep down the valleys, often
Joining similar streams from adjacent
valleys. They may be likened to the
branches OF tree, gathering into
common trunk. Tho glaciers Of Green
land, on the contrary, chiefly spring
from all icecap, which covers the whole
Interior. From this ioecap tongues creep
out in all directions, Instead Of several
snow fields gathering to form one gla.
cier one snow field sends out many gla-
ciers. Tho great icecap of Greenland
puts forth some hundreds Of glaciers.
There are, however, glaciers Of the AL
pine type in Greenland.
One OF the more obvious characters
tics of most Of the glaciers l studied is
their termination in vertical faces, even
when they end ON the land. Most
known glaciers slope down to thin
edge at their extremities, These com.
monty, not always, end in vertical cliffs
of Ice 100 10 100 feet high. The sides
also are frequently vertical. BY reason
OF this they reveal many features that
are usually concealed. have never be-
fore seen glaciers that presented such
admirable facilities for Investigation as
those of this northern region. The most
striking structural feature revealed by
those vertical faces is the pronounced
qualification of the basal ice.
Not only is the ice definitely bedded,
but the rocky and earthly material which
the glaciers carry in their bases Is ar.
ranged In layers. In some cases the lay,
ers are twisted and comforted, and in
others they are showed over each other.
The detailed study of these gives many
clues to the modus operandi of the ice
action. The rate of movement of the
ice generally is very slow. In u few Of
the more vigorous glaciers, where action
is concentrated and intensified, the
movement is considerable, but on the
average it is probably quite safe to say
that the movement of the ice boarder is
less than a foot q dav rrohahlv Ieas