Abbeville progress., 1914-06-06
GEOLOGICAL PUZZLE.
South American water Stone"
a Singular Phenomenon.
Scientists Disagree as to Process o?
Its Formation-Principal Constitu-
ent Is Silica-ls Found En-
bedded in Black Lava.

There IS found in Uruguay and the
Argentine Republic a geological puz-
zle known to the English-syraking
people OF those countries as ",he SaIto
wafer stone"
IN appearance the average water
stone resembles piece of clear glass
that has been fused by hea;. The
stones vary IL size from the bulk OF
larks egg 70 that of d goose but
larger specimens are sometimes found
They are not uniform in shape are
slightly tiattened, and all are more
or less coHtOrJed Ii is thought that
the principal constituent OF the stone
Is silica. The rock in which il is
found embedded is dense black lava
Many stones contain no water. and
the more or less imperfect stones
seem TO be numerous These imper-
iect stones. however. serve. iu "A meas
ure' to indicate how the water stone
Is formed. For example. the appear
anGe OF one stone clearly indicates
that the first formation of the stone
was abruptly stopped by some un-
known cause When observed from
the cOncave side it presents somewhat
the appearance of a coniCal seasheu,
displaying irregular concentric circles.
In the center OF these circles there is
a rounded indentation which indicates
win comparative certainty that the
lnhltration of water holding silica in
solution Is the cause of its formation
As already stated. the water stones
are found embedded in black lava
rock. which at one period was soft
ana pilant from volcanic heat Silica
IN molten state may have dripped
on 1t, possibly falling from a great
helght; and as this dripping continued
TO bear on one point, the silica. which
slightly broadening out. would be de-
pressed in the center, thus causing the
underslde to become convex or
pointed, and the continued augmenta-
tlon or material would cause the silica
gradually to sink in the lava
Molten silica in cooling possesses
the property OF remaining for some
time in soft, gelatinous condition,
but in heated atmosphere it would
remain plant infinitely longer. Thus
as the silica continued to sink the
lateral pressure of the lava on the
silica gradually brought its upper
edges together and by the continued
dripping of the molten silica the close
ultimately became hermetic.
All this is theoretical, however,
since scientists are not agreed upon
the question. If the formation of the
water stones is to be traced to the
more direct action of molten silica.
the water they contain must have
found its way In by some means after
the stone was formed. If this be the
case, there seems to be only one ra-
tional solution OF the problem-that
the stone after completion must have
been submerged in water for a long
time, possibly warm water, the heat
OF which would have caused a slight
expansion in the silica. This being
united with pressure, in time the wa
ter may have filtered through TO such
an extent as finally to fill the cavity.
Many hold that the water stone is
fraud, since, they assert, if it be
left exposed for any length of time
the water it contains will gradually
evaporate and finally disappear. But,
on the other hand, those who admit
that various cases of this have oc,
CURED point out that the evaporation
of the water In all these instances was
probably due to a slight fracture in
the stone. the result of carelessness or
want of skill in the excavation.
1t is also pointed out that there are
many water stones that have lain in
museums and elsewhere from IL to 10
years. and that during that compare,
lively long period the water in the
stones has shown no perceptible dimi,
mutton. This, it is contended. is suffi.
cient proof that the water stone is not
a fraud. but a very singular phenoID
enon.