Evening star., 1948-04-19
Stars, Men and Atoms
Ton Of Rock Brought Back
From Antarctic for Study
U. S. Research Involving Uranium
Does Not Involve A.Bomb
By Thomas r. Henry

By Thomas r. Henry
Nearly ton Of Antarctic rocks belonging
generally to the granite family. were brought
back by the Navy icebreaker Edisto, flagship
Of the ls47-4S Antarctic expedition.
The object is to determine the age Of vari.
Gus polar areas by determining the ratio BE-
tween the uranium and lead in this rock.
In other words the rocks have been brought
back because Of their uranium content. but
what Navy and Geological Survey want par.
ticularly emphasized Is that they are not par.
ticularly interested In It's uranium content -
q guide to the possible value Of the Antarctic
continent as q source for the chief basic ma.
terials Of the atomic bomb
When the Nays ls46-47 expedition was IN.
nounced, together with prospective Russian.
British, Norwegian and Chilean expeditions.
there was an unfortunate suggestion that IL
was uranium race" The Idea was unbe.
lievably silly. At least 80 per cent OF the cone
tinent is buried under Ice and most OF this ice
is at least mile thick. There would Be no
possible way Of locating radioactive element
under such blanket. Even multibilhon volt
cosmic rays could not penetrate 1t.
But even II q means were found Of locating
uranium deposits the problem Of mining tho
metal would be impossible. Search In the less
than one per cent of rocks free Of Ice naturally
would be futile.
Uranium Is Common.
There doubtless will be uranium IN the
rocks brought back from the Bunger oasis
and from various other shore points. There
also is uranium in almost everybody's back
yard The element is widely distributed
through the crust of the earth at an approx
innate rate of about one atom to 100000. In
only few places is there sufficient concen.
tration to make mining feasible
But besides it's value for atomic bombs
uranium Is the "clock" of creation. BY
series of radioactive disintegrations over
period Of several billion years half the uranium
in any given deposit will turn into lead.
The process is continual Some Of the uranium
atoms are disintegrating every second. Thus
by determining the ratio Of certain kind
of lead-not the same as ordinary lead but
with the same chemical reactions-to uranium
in rock 1t is possible to calculate the span
OF time since that rock was formed. pro-
viding 1t is matter OF several million years.
The technique has been described as SINH.
lar to determining the age OF city by cheek.
ing the gravestones in its cemeteries. Every
lead atom is the corpse Of uranium atom
The work will be done by the Geological
Survey. There is the odd chance IN few
billion, of course, that such an area as
Burgers oasis, q 2o0-square-mile area from
which ice has retreated, might be found rich
in uranium The chances are no greater
than finding flower bed rich in the explod-
ing element.
Once Was Tropical Ares.
This situation k understood by Russians,
British, Japanese and everybody else mentioned
in connection with Antarctica. No government
will spend a cent looking for ninable uranium
around the South Pole. The chances OF finding
it in any city park in the United States are
much better.
The geological interest in Antarctca, how
ever, is something else again. Once 1t was
tropical land, very likely crossed by the equator
when the South Pole was in central Africa.
That was in the Permian geological period.
about 100000 600 years ago. 1t formed part OF
the mysterious super continent Of Gondwana-
land which split apart in what must have
been the greatest upheaval In the earths his.
tory. ''se sF'
Just what happened nobody knows. Detssnai-
nation OF rock ages might prove Of considerable
value in clearer understanding Bringing back
the rock was Navy service to science and
nothing more 1t has nothing to do with any
problem of national defense or atomic energy.