The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1897-05-23
HOW CONTINENTS WE'RE FORMED.
Scientific Explanation of the Growth
of Land Now Comprising the Earth.
Harper's Magazine

Harper's Magazine.
If molten matter exists beneath the crust
of the earth it must contract on cooling,
and in so doing it must disturb the level
of the portion of the crust already solidi-
fled. But an important difference of opin-
ion. arose as to the exact rationale OF such
changes. Hutton, and practically every one
else who accepted his theory, had supposed
that there were long periods of relative re-
pose during which the level of the crust
is undisturbed, followed by short periods
OF active distress, when continents are
thrown UP with volcanic SuddenneSS, as by
the throes of a gigantic earthquake. But
now comes Charles Lyell with his famous
extension of the uniformitarian' doctrine,
claiming that past changes or the earth
surface have been like present changes in
degree as we'll as kind The making of
continents and mountains ne said, is going
on as rapidly to-day as at any time in the
past. There have been no gigantic cata-
clysmic upheavals at any time, but all
changes in level of the strata as q whole
have been gradual, by slow oscillation, or
at most by repeated earthquake shocks
such are still often experienced.
In support of this very startling cOnten-
ton Lyel gathered a mass of evidence of
the recent changes in level of continental
areas. He corroborated by personal inspec-
ton the claim which had been made by
Playfair in 1902 and by Won Bush in 1907
that the coast line of Sweden is rising at
the rate of from a few inches to several
feet in a century. He cited Darwin's OBJ
serVations going to prove that Patagonia is
similarly rising, and Pingefs claim that
Greenland is slowly sinking. Proof as to
sudden changes of level of several feet,
over large areas due to earthquakes was
brought forward in abundance. Cumulative
evidence left it no longer open to question
that such oscillatory changes of level,
either upward or downward, are quite the
rule, and it could not be denied that these
observed changes, if continued long enough
in one direction, would produce the highest
The possibility that the making of even
the highest ranges of mountains had been
accomplished without exaggerated catas-
trophic action came to be freely admitted.
1t became clear that the supposedly stable
land surfaces are in reality much more va
riable than the surface of the shifting
sea- that the continental masses, SEEM
ingly so fixed. are really rising and falling
III pillows thousands of feet in height, ages
being consumed in the sweep between crest
and hollow
These slow oscillations of land surfaces
being understood, many geological enigmas
We're made clear-Such the alienation of
marine and fresh water formations in
vertical series, which CuVier and Erong-
Mart had observed near Paris; or the
sandwiching of layers OF coal, or subaerial
formation between LAYERS of subaoueous
clay or sandstone which may be observed
everywhere in the coal measures. In par
ticuar the extreme thickness of the sedi-
ceedins the depth of the deepest known
sea- was for the first time eXplicabe when
it understood that such strata had
formed in slowly sinking ocean beds.
All doubts as to the mode or origin of
stratfied rocks being thus removed, the
way was opened for a more favorable con-
sideration of that other Huttonian doctrine
of the extremely slow denudation or land
surfaces. The enormous amount of land
erosion will be patent to anyone who uses
his eyes ntellgently in a mountain dis
trict. 1t will be evident in any region where
the strata are tilted-as, for example the
Alleghenies-that great folds of strata
which must once have risen miles in
height have in many cases been worn en-
tirely away, so that now a valley marks
the location Of the former emnence. Where
the strata are level, as in the case of the
mountains of Sicily the Scotch highlands
and the familiar Catskills. the evidence of
denudation is. if possible. even more
marked; for here it is clear that elevation
and valley have been carved by the ele-
ments out of land that rose from the sea
as level plateaus.