Evening star., 1936-01-07
STARS, MEN AND ATOMS
Notebook of Science Progress in Field,
Laboratory and Study.
BY THOMAS r. HENRY.

A new theory of mountain building
and sinking is proposed by Dr. William
Bowie, chief of the Geodetic Section of
the Coast and Geodetic Survey.
The phenomenon of synchronous ris-
ing and falling of the great ranges-now
towering in the clouds and now forming
part of the bottom of the Sea-can be
accounted for adequately, Dr. Bowie
holds. from the titanic cumulative effects
of erosion and sedimentation. The ac-
emulation of sedimentary material
washed off the surface of the earth by
the rains and deposited at the shore
lines overweighs the plastic inner sur
face of the earth below the 60-mile-thick
blanket of light crust.
Hence the deposits sink, like loaded
boat in the water. AS they sink they are
carried down to warmer regions. The
heat causes them to expand and push
upward. Thus a mountain range is
formed. But then the expended region
once more is in a cooler environment
and proceeds to shrink-so much so that
it is below sea level and the ocean waters
rush in and cover it. Even now the APP
palachians and Rockies may be cooling
and contracting, like loaves of bread
It is well known, says DR.. Bowie, that
the part of the earths surface which
now forms the tops of the mountain
ranges several times in the geological
past has constituted part of the floor
of the ocean. Fossils of marine crea-
lures in the rocks of the high peaks is
itself sufficient evidence of this. The
rising and falling may occur in vast
nv mil NJ
years
Although the hypothesis is admittedly
difficult to prove and the cause of noun
tain building is a matter of considerable
dispute among biologists, DR.. Bowie is
enabled tc fit the process into the gen.
eral theory of iSoStacy-that the crust
of the earth floats on plastic material
mighty like sheet of ice over the Arctic
ocean-which now is widely accepted.
The theory provides for SUFFICIENT ter
restial forces to cause the phenomenon.
I'VE know" says DR.. Bowie. that we
now have rainfall at the rate OF ap-
proximately 80 inches a year over the
land surface Of the earth. 1t is many
times that in some areas and in others
there is scarcely any rain at all BY
using an average of 80 inches we would
have at that rate approximately l mile
of rain in 1000 years. But since the
sedimentary age is $50 900 times that
much we can see that if the rate Of
rainfall has been uniform there could
have been 100000 miles of rain.
THE rain falling on the earth carries
to the ocean waters vast quantities OF
material in suspension and solution.
According to the results of analyses Of
river waters by scientists Of the Geo.
logical Survey the mass of material that
goes to tidewater in 1900 years from
the United States alone is equivalent
to blanket one foot in thickness over
this country. This rate is small In
terms of the length Of human life, but
in geological times that amount OF
erosion that would have occurred is
enormous. One mile of erosion would
have occurred in $4,000, 600 years, if the
configuration Of the surface OF the
United States could have been MAIN
tanned as it now is. But this is only
about one thirty-f1fth of the total time
during which there has been erosion,
rainfall and sedimentation.
Great piles of sediment are accumu-
lated at the mouths of rivers, in inland
seas and lakes. and along our shores.
These accumulations rtainly affect the