Evening star., 1933-07-22
Evidence Left in Rocks Is
Clue Being Offered in
Gathering Here.
HUMAN RACE IS HELD
COMPARATIVELY YOUNG
Three Fourths Of Time as Known
by Nan Is Almost Com.
plete Blank.
BY THOMAS r. HENRY,

The vast twilight Of time since the
earth began is engaging the attention
Of the worlds foremost geologists at
the opening sessions of the Interna-
tional Geological Congress at the
United States Chamber OF Commerce
Building this afternoon.
The chief topic of discussion was that
OF fixing the age Of the earth through
evidence the f1eeting years have left in
the rocks. The general agreement is
that about two billion years have
elapsed since a little ball of fire was
hurled OH the sun due to contact with
q passing star into the coldness of outer
space where it became Mother Earth.
There has been time for fifty million
generations Of men since the beginning
but the geologists were agreed that
actually man was a very late conner.
Probably little more than two million
years. at the utmost, have passed since
the earliest rude ancestors Of the human
race appeared somewhere in the old
world.
Almost Complete Blank.
From the discussions today it was
brought out that three-fourths Of the
time since the beginning Is almost q
complete blank. The whole earth was
q barren, Ifeless desert. The rocks
dating from that period show no eN-
dence Of any living thing The first
evidences Of life are found less than
half billion years ago, in the geologi-
cal era known as the Lower Cambrian,
although it is probable that plants or
animals which left no traces in the
rocks had existed before that.
The first life was complex and at q
high stage of development, according
to the fossils left in the rocks, and the
real beginning Is mystery to both
biologists and biologists. In the re-
ports being presented this afternoon
the progress of time IS being followed
through the first inhabitants of the
dry land-remote ancestors of the
frogs and toads-to the age of the
monStrous reptiles while the great coal
deposits were being laid down. and,
mllllons OF years later, to the appear
ance Of the first warm -blooded birds and
mammals.
Measures Disintegration.
DR.. Alfred c. Lane of Tufts College
has report on the progress made
IN measuring the age of the earth
through the disintegration of radium,
thorium, actinium and other radio
active elements. The atoms of these
elements are so heavy and complex that
s~ASAA SASSeA oAAo o4AA P4OOO41o CdlulOt SGlCk
together. They break up, eventually
forming certain kinds OF lead. The
rate Of the process is known From
the amount of of the right kind of
lead IN a deposit Of radioactive ma
ter1al the biologists can tell the amount
OF time it has been disintegrating.
Prof. ]. j. Sederholm Is presenting
before the congress the latest results
In the measurement of time before the
beginnings of life. During all this
billion and half years the geologist
and he cannot arrange time in any
convenient units.
Another method of measuring time in
the fairly recent past, geologically speak
ing, is being presented by the Swedish
geologiSt Ernest Antevs. This is by
study of the waves" or deposits Of
sediment left In ancient lakes by the
melting ice of the glaciers as they re-
treated northward.
Study Appalachians.
The other topic under discussion this
afternoon was the geological history Of
the Appalachian Mountains from New
England to Georgia. There are the
newer and the older Appalachians, it
was brought out in the papers. The
former consists largely of rocks laid
down since the beginning OF life, while
the material of the present mountains
was on the bottom of an ancient sea.
The latter consists of rocks, dating from
more than 500 ,OO0,o years ago. The
older province includes much Of the
Blue Ridge and Appalachian areas.
The meetings of the congress opened
at IL am with an address Of welcome
by A. L. Hall, assistant director of the
Geological Survey of South Africa and
general secretary Of the last interna-
tional congress. There was then an
address by Waldemar Lindgren. pro-
fessor of geology at the Massachusetts
Institute of Technology, who was
elected president of the congress.
Other officers elected at the morning
session were: General secretary, w. c.
Mendenhall, director of the Geological
Survey; treasurer, E. G. Mathews, pro-
fessor of geology at Johns Hopkins.