Richmond daily palladium. [volume] (Richmond, Ind.) 1876-1904, 1901-11-12
WEARoFTHE EARTH
HOW The FACE OF our GLOBE IS
CONTINUALLY CHANGING.


Geological Agents Tint Arc siwa-s
Busy Ina Natures Great Workshop
where Man Has Comparasi~eis Ls.-
tie InAaence.
The atmosphere plays its part in geo
logical operations. Its correcting p~w-
er, backed by rain and wind. helps 10
decay and disintegrate those rocks
which are exposed TO its influence. Ram
completes the work thus begun. Wind
blows dust. sand and volcanic ashes
over large tracts Of earth-in fast,
over The whole Of it,
1t is only of late years that geoio-
gists have discovered that fine vol
eanic dust is carried over the whole Q:
the eartli's surface an. plays very
important part in the deep sea depos-
it's On deserts and nearly rainless r.
gions blown sand will wear away the
hardest rocks by beating against
Them Some sandstone formations APP
pear to have been piled M by winds.
Winds cause ocean currents, waves
and storms. The great denudine
power of the sea is largely due To the
atmosphere. Some parts of the Eng
lish coasts are being rapidly washed
away Plants and animals have their
distribution considerably affected py
winds and ocean currents, Again.
whether living in water or on land.
animals live on the oxygen supplied
from the atmosphere. and land plants
absorb earbonie acid from the same
source.
Rain acts in two ways: eli chemic-
ally by dissolving certain substances
such as lime, out of the rocks and -.
mechanically by wearing down their
surfaces as il flows over them. Any
old building-a ruined castle or cathe-
dral. for instance-shows a wealth
cred" surface resulting from the ac-
ton of rain and wind. In sandstone
structures the details of carving are
often lost, and on old tombstones the
lettering can hardly be deciphered-
Springs are due to rainwater collecting
in rocks and rising to the surface.
Rivers are fed by rains and springs.
A river is "A very powerful geological
agent. In the hardest rocks rivers
gradually carve out valley or gorge
This is accomplished partly by chemic-
stances. but chiefly by mechanical
erosion. the stones, sand and mud
wearing away the bed OF a stream as
they run and tumble over 1t.
The finest examples Of river action
are the famous canyons of Colorado.
which In some places are gorges 5000
or even 5000 feet deep. with vertical
sides But. as already pointed out.
rivers have a constructive action quite
as important as their destructive ac-
ton. BY bringing down their burden
of sediment into lakes. estuaries and
seas they build up great piles of rock
and SOW the dust of continents to
be-"
Glaciers are rivers of ice fed by the
eternal SHOWS of high mountain
ranges such as the Alps. They wear
out their own valleys as rivers do,
they transport mud. sand and stones to
great distances. in some cases sending
them sealed up In icebergs to float far
out 20 sea and on melting deposit their
burdens on the sea floor. on the coast
of Newfoundland northern icebergs
are depositing great mass of ..gla-
cial drift"
The sea Is a great denuding agent.
but it's work is more constructive than
destructive. 1t is the workshop where
nearly all the stratified rocks have
been accumulated and ranged In layers
or strata. The rivers and ocean cur
rents continually bring in fresh sup
plies of debris even for hundreds Of
miles.
Man, compared with the lower AMI
mals.Jproduces but little effect as ge-
illogical agent. Still the human race
has considerably modified the distribu-
ton Of plants by cutting down forests
and by cultivating certain plants to
supply food So with animals. Ger
tain useful species have been culfivat-
ed and enormously increased at the
expense OF others which prove useless
or harmful.
But plants and animals have had.
and still have. far more influence geo
logically Coal seams are made up Of
vegetable remains of former periods
Forests have an important influence
on climate and on animal as well as
plant life. In the comparatively IN
known world of the ocean marine
plants doubtless have important func-
lions.
Marine animals accomplish a vast
amount OF geological constructive
work. Great deposits thousands of
feet thick owe their existence to small
calcareous creatures living i'm the sea-
Coral reefs afford the most familiar
The force known as heat Is OF great
Importance. The earth is hotter below
the surface and probably has very
high temperature toward its center.
In some places not very far below its
surface il contains highly heated rock.
which occasionally flows over the sur
lace during volcanic erupfions In
,ther places we find hot springs in con-
1ection with volcanic action.
Heat exercises powerful influence
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