Evening star., 1933-07-26
LARGEST AMERICAN
|QUAKE IN HISTORY
STILL IN PROGRESS
Reports of Shocks Lasting
Six Months Made to &C.
ologicaI Congress.
DISTURBANCE OF EARTH
IN SOUTHWEST NEVADA
Occurrence in Thinly Populated
Area Saves Nation From
Great Catastrophe. j.
BY THOMAS r. HENRY.


| from the first big shock, it was reported
| to the International Geological Con-
gress today by Eugene Callaghan Of the
United States Geological Survey and
Vincent P. Gianella of the University Of
Nevada.
The big shock came on New Year
eve. Only the fact that it occerred in
very thinly populated area saved the
| country from one of the greatest
catastrophes in its history. Actually
nobody was killed and only few iso-
lated cabins demolished. There were
no towns near the center. But 1t
changed the flow of springs. sent ava
| lanches Of boulders down mountain
sides, churned the surface of the soil,
and in some cases threw up boulders
out of the earth. Clearly perceptible
shocks were felt over an area Of 400, 900
square miles and barely perceptible ones
were reported within q million square
miles.
Thousand Secondary Shocks.
The main shock has been followed by
literally thousands Of secondary shocks
within the area. The last reported was
a week ago. Rumbling Of the earth is
heard with the shocks, and sometimes
strange noises without any shocks. Un-
| questionably, it was reported. titanic
| forces are at work in the depths Of the
earth and the foundations Of vast noun
tains are being shaken.
The two geologists have been making
an intensive study Of this earthquake.
| Its center was in q hilly valley sur
rounded by high mountains in South
western Nevada. The origin Of the
shock is believed to have been very deep
| in the earth which accounts partly Tor
| the very little damage done.
| This shock, it was explained, may be-
| long to the same general earthquake
| family as those which occasionally dev-
astate thickly populated sections OF
California, due to the general disequi-
librium of the foundation blocks OF the
Rocky Mountain region.
A new time clock" Of earth evolu-
ton in the form OF volcanic rock de-
posits in the Appalachian Mountain re-
gion was described by DR.. r. r. Rosen-
krans of the Pennsylvania State Col
! lege. Ordinarily q geological area Us
dated by the fossil animals found In
| the rocks-mostly Of the sea-shell type.
But this Is sometimes unreliable be-
cause two radically different animals
| of the same general family may have
! lived simultaneously in adjacent valleys
This was particularly the case IN the
| Appalachians.
| In Ordovician Period.
But it so happened that during the
Ordovician period, about 100000, 900
years ago, this particular part Of the
country was subject to a long series OF
| volcanic eruptions. Great ash erup-
tions fell over large areas. These
eventually hardened into a rock known
as bentonite. Deposits have been found
in Kentucky. Alabama, Ohio, Tennessee,
Virginia, West Virginia, Maryland,
Pennsylvania, New York, Wisconsin.
In some cases it is possible to distin-
guish the beds caused by different ash
falls. Some are thicker than others,
, while in some cases there Is believed tc
be different physical and chemical COM
position. If different animals are found
| associated with bentonite from the
same volcanic eruption 1t Is indicated
| clearly that they were simultaneous in
time, whereas otherwise they might be
| put millions Of years apart.
DR.. Edward B. Mathews Of Johns
Hopkins University offered suggestions
for seeking buried treasure In the depths
Of the earth, such as emeralds, saphires,
| rubies and radium. The most likely
place, he said, Is where giant cork
screws, or batholiths. have forced their
way spirally to the surface from deep
within the earth. They force the
rocks where they originally are formed
| and carry them in concentrated form to
the surface. These batholiths are some
times bottomless, straight columns of
| granite. They form the cores Of
mountain ranges and, in old mountains,
! have been exposed by the washing away
| of the over lying rock layers.
Series of Floods Due.
| Of great floods in the future, If it can be
| judged from what has happened in the
past, DR.. A. w. Grabeau Of the Chinese
Geological Survey told the congress.
The level of the sea has periodically
risen and fallen, in regular rhythm
like that of breathing, for the past half
billion years, DR.. Grabeau said. This
phenomenon can be traced back to the
Cambrian geological period, the dawn
of life on earth. The cause Of these
periodic floods IS not known, DR.
Grabeau said, but may be linked with
| the activity of radioactive substances,
such as radium. deep within the earth
This radio activity probably generates
and there Is evidence that the heat may
escape at intervals, with the result that
there are q series Of cataclysms.
| The fact that the oceans have often
covered the present continents IN the
past is well known to geologists, but II
usually has been attributed to the sink
| ing of the land. DR.. Grabeau said
| however, that all the evidence indicates
| that the real cause has been the rise
and fall of the sea level every few mil
lion years. Some areas Of the continent
have fallen and others have risen, but
this has been only secondary to the
ocean movements.
| A series of gradual, periodic rises fol-
lowed by slow periods Of recession of the
waters can be traced in the old rocks
of all the continents by two methods, he
] added. One is by the layers of overlap
ping sediments laid down in succession,
one on top of the other, as the seas
gradually advance farther and farther
inland The receding water left sedi-
ments also, but these were laid down in
layers in reverse fashion. The layers
left by both incoming and outgoing
waters. long since hardened into rock
can be distinguished from each other
and their age determined.
Offer Dating Means.
Fossils of extinct animals in the
sedimentary layers also offer means OF
dating them. DR.. Grabeau believes that
these floods had an important effect
on evolution in the early days Of life.
"As the waters pushed inland like
slow-motion tidal waves lasting millions
of years." he said, "the areas Of dry
land were narrowed down and shore
districts and continental shelves con-