Evening star., 1953-01-02
Man Finally Successful
In Making Real Granite
Nature Hos Been Producing
Il for Years Under Eorth

Mature Hos Been Producing
It for Years Under Forth
By Thomas R. Henry
Man finally has succeed in making
granite.
Nature has been making it for 8 or 4
billion years in the boiling heat miles
under the earth and then thrusting
1t upward to make mountains.
It is about the commonest and most
familiar rock in the earth's crusC.
For some years Natures process has
been major problem of the Geophysi-
cal Laboratory of the Carnegie Institu-
ton Of Washington, concerned primarily
in finding out how the earth was made.
Now Drs. N. L. Bowen and N. r. futile
have succeeded in crystallizing boiling
mixtures Of silicon, potassium. sodium
and aluminium to produce minute
amounts Of material which cannot be
distinguished from the purest sort of
granite under a microscope.
Granite is essentially a mixture of
quartz and feldspar. Quartz is usually
the most abundant element It is silicon,
combined with oxygen. There are two
kinds Of feldSpars, sodium aluminium
and potassium aluminium. The Geophysi-
cal Laboratory scientists first carried
out extensive investigations of the re-
quirements for producing each of these
three major constituents and getting
them in the form of crystals.
The crust Of the earth floats on an
ocean Of extremely viscous liquid 10
miles or more deep. Actually this Liquid"
Is probably something hard and brittle
like glass. also considered a sort Of
liquid. The temperature in the far
depths Of the earth, increasing at a rate
OF SIS degrees centigrated per mile, Is
SUFFICIENT to melt anything. But the
pressure OF the weight Of nine or ten
miles Of the earth's crust is so great that
something like the glass-like material Is
produced. Drs. Bowen and Tuttle cali it
the mother liquor" When pressure is
released, for whatever reason, this
mother liquor is spouted out of the earth
as volcanic lava. It cools rapidly into a
glaSs-like material such as obsidian. It
never turns into a granite. .
Like Old New England Drink.
New England farmers used to make a
very potent drink by setting bucketftH
OF hard cider out in below zero tempera-
ture for few nights. Then they would
bore through the ice and pour out the
liquid which remained in the bottom-a
sort OF super-applejack. Mother earth
preceded them in this particular form
OF moonshining. The hard cider, accord
ing to the GeophySical Laboratory scien-
lists. might be compared to the mother
liquor and the granite to the ice which
forms progressively deeper and deeper
on top of the bucket.
ThlS. OF course, is greatly Simplified
comparison. The various constituents
which make up granite could not be
cryStallized, or frozen into q real solid
by duplicating In the laboratory the heat
and presSures under which the mother
liquor exists. It was determined some
years ago that the missing factor was
water trapped in the mother LIQUOR. but
water IN a form never known at the
earth'S surface. It Is steam under a
pressure OF 1900 or more times the
weight OF the atmosphere per square inch
at the earth's surface. This is a material
which. other Geophysical Laboratory
experiments have shown, has unique
properties which after years of work
nave not been fully explored. Such water
added to the molten mixture of the
clements that make up granite is neces-
sary to produce their capitalization "in
any reasonable time," Drs. Bowen and
Tuttle say. The pressure is that which
exists at depth Of nine miles but their
work was accomplished at a somewhat
higher temperature than that of the
mother liquor" at such depth. -
just what the water does is still a
problem. For one thing, the Carnegie
geophySicistS say, it. reduces somewhat
the viscosity of the glass-like mother
liquor. 1t also, although this function
still is obscure, probably acts as a chemi-
cal catalyst. something necessary for a
chemical reaction which does not itself
enter the finished product. At any rate
crystallization will not proceed satisfac-
torily without it.
Origin Is Uns0lved Problem.
The origin Of the mother liquor itself
is problem still unsolved. The most
satisfactory explanation at. present is
that it is formed from the melting of
Sedimentary rocks, laid down on sea
bottoms by sediments from the conti-
nents over countless centuries. These
are eventually thrust deep by the earth's
upheavalS to the final depths where they
are melted.
The granite presumably comes from
the extreme upper levels Of this mother
liquid, the froth on its surface. The
capitalization reaction presumably would
not go on at much higher temperatures
and pressures.
The material made at the Geophysical
Laboratory probably wouldn't look much
like the granite with which folks gen.
orally are familiar. The crystals are finer
and they have none Of the impurities.
All sorts Of elements. presumably origi-
nally present in the mother liquor or
picked up at some stage Of the trans
formation. are present in the GRANTEES
which make mountains. These are, for
example. the source of most radioactive
materials. They merely complicate the
crystallization problem.