Knoxville journal. [volume] (Knoxville, Iowa) 1874-1986, 1875-12-02
The Origin OF Mountains.


wafer from the erosion OF wasting con-
tinent which By upheayal have become
mountains The other il that they are
due TO upiifts, a. the result OF lateral
pressure caused by shrinkage Of the earth's
anterior. For the last fifteen years or
more these conflicting views have each
been held by gcologists Of undisputed au-
,thority and !" when doctors disagree who
shall decidey" Is the old question which
remains still unanswered. This uncer-
sainty In all moral reasoning, when we
have 10 balance probabilities, IL grest
source Of discomfort TO the youthful
student. and perhaps In no department Of
human inquiry Is this more true than In
the field Of science, for what IL highly
probable to-day may be shown In the light
OF advancing science 70 be highly I'm.
probable tomorrow. And In reply 10 the
oft-repeated question of the young student:
"Wbat ID the use Of learning as truth To-
day what may be rejected AZ error To-
morrow ~ IL may he said that all the sue
cessiye theories Of advancing science are
sicpplng.stones which may eventually
lead ~ the undoubted truth. We see Use
in taxing the first faltering and ill.alyiscd
steps 10 any ayncatlon, though we soon
rejects these for others more conducive 10
thc end desired.
Without attempting decision, we pro
pose in tins article only 10 state some 81
the main points in the arguments pro and
cop, and leave all TO decide for themselves
as 10 which Ii the more reasonable.
We would naturally conclude that, If
mountains are due TO lateral pressure,
they would he formed by the uplifts or
elevations Of the earth's crust But THIS
is seldom the fact, for several reasons.
According 10 Prof Dana, many If not all
the mountains have their origin in the
bending down Of the crust. AS The crust
subsidized, the trough was kept fuH OF
water, which continually deposited sedi.
smcnt. This deposition about kept pace
with the rate of subsistence. In this man
ncr many Of our mountain ranges were, IN
the earlier ages, taking the initiatory
steps In the process Of mountain. making.
As'the crust subsidized and was covered 10
great depth with a0 accumulation Of
croded material, IL would be weakened by
the earth's internal heat An addition OF
several thousand feet Of sediment 10 the
surface would bring given degree Of
heat 50 many thousand feet nearer the sur
face This would often be sufficient 10
soften or melt the sustaining crust, which
would then yield before the lateral and
vertical pressure combined and cause the
crusis on the sides Of the trough 10 fold
over and approach each other above 1t,
thus crushing the sediIncntary beds into a
narrower space, with the necessary result
Of cleyaiing the crushed and folded strata
in fbc middle.
The Appalachian chain illustrates the
fact that one mountain system may be
formed by several successive deprcssions,
accompanied with the deposition Of croded
material Prof Hall attributes the cause
of mountain. making TO sedimeDtary nc.
foundations, which, by their weight, are
sufficient to cause depression in the
crust. Thus, by the addition Of 10000
feet Of sediment the crust would sink the
same number Of feet. Then, by subse.
quent elevation Of the crust, the accnmu-
lated strata would be raised into mount
ain, independent Of lateral pressure. He
Just fcyerscs the idea Of Dana, by making
The subsidcncc consequence OF sediment
AIRY Accommodations, instead OF the &C.
cumulaiions consequence OF subsistence
10 this Dana objects, because " the earth's
crust would have Ia yield like film ol
rubber 10 have sunk foot for every added
foot of accumulation over Ia surface, and
mountains would have had no standing
place"
Another reason why the elevations due
10 lateral pressure do not produce the high
mountains appears Ia the fact that, when
"A series Of strata " sharply bent upward
forming an anticlinal--ihe outer strata
are fractured and strained apart, while The
strata which are bent dOwnward-form
ing "A synclinal~.present 30 the surface q
firm and compact mass. This Can
be clearly shown by making .
sudden bend In walking.stick
fFrL.. Ubara ~ tI,n nrtsp .ttryn xaiII h,,t torn
asunder, leaving splntered and ragged
surface, while on the inner curve they
will become unusually dense and firm
The fractured edges Of the anticlinal
curve are In favorable condition 10 b,
worn away by water, while the compact
surface Of tho synclinais, though forming
the valleys where the greatest amount ol
running winter would act upon IT, suffers
but little erosion. The consequence Ii
that the elevated strata are worn away
even below the level Of the original val
ieys, and the latter become the elevations
This can be proved by noticing that Tn,
strata visible on the sides Of most valleys
and hills are not parallel 10 the sides, but
are nearly at right angles TO them.
Tie mountains formed by dcpressions
Of the crust were far more common In the
early history Of scdimentary deposit, ioi
she crust WINS then comparatively thin
and hence more yielding To lateral press
ure. But after The crust became thick
,ened beneath by the cooling Of the earth
and more rigid by the accumulation ol
strata above and by previous pication and
qualification, the mountains formed wer,
largely due 10 upliits Of very wide extent
carrying the stratihed deposits with them
Our Rocky Mountain system was formed
by these upliils In the tertiary age, and II
IL probable that coral island subsidences
In the Pacific Ocean accompanied tn,
continental elevations.
The adhercnts to the accumulation the.
ory--among whom are Hall and Hunt on
this continent and Scrope and Lycll In
Europe--have noticed that In mountainous
districts the elevations are less than the
aggregate thickness Of the strata, while In
non mountainous sections the heights cor.
respond TO the thickness of the strata. III
the latter were equally true In mountain.
Gus districts, the Appalachian Mountains
would attain height Of 40, 900 feet. Mr.
Hall holds that these barriers are due 10
original deposition of materials and not
10 any subsequent forces breaking up or
disturbing the strata Of which II Is com.
posed and that upheavals and contor.