The Coolidge examiner., 1936-11-13

Prepared by National Geographic Society.
Washington, d. C.-WNU Service.
A S ONE stands upon tn e
~ heights of the San Andres
mountains in the neighbor-
hood of Rhodes Pass, New
Mexico, one looks out upon an ocean
of white South and east stretches a
vast sea on which the CLINT of white
caps appears as real as the rocky
shores. The view is startling
mirage. Closer inspection reveals
that the billowing snowy expanse is
the White Sands of Alamogordo.
The windrowlike dunes seem vel
vety in their softness, yet many of
them are firm enough to permit
motorists to roll their cars from one
crest to the next in roller-coaster
fashion Some of the hills have at
tanned a height of 100 feet, but so
feet probably represents the aver
age.
Curious stories of the origin of the
sands have circulated since they
have been known to Americans, but
the truth is not less interesting than
the fanciful explanations The proc
esses of making are going on con-
Stantly.
Underlying the Tularosa basin are
hnIc nf Dor,,oiar
sandstone, between the layers of
which are interspersed thick beds
of gypsum. Borings made in recent
years reveal that the gypsum is
hundreds of feet below the present
valley floor and that water is en-
countered at depths of thousand
feet or less.
The nature of the sedimentary
rocks above the water-bearing sands
is favorable to upward seepage. AS
the water on it's upward course
passes through the gypsum de-
posits, it dissolves that material and
carries a rather full load to the
surface. The limestone through
which the solution passes is not
readily soluble; very little in addi-
ton to gypsum is carried by the
rising water. When evaporation
takes place at the surface a fairly
pure crust of gypsum is deposited,
which, under action of the atmos-
phere, crumbleS to form crystalline
grains.
The prevailing southwest wind
sweeps these crystals from the sur
face upon which they were formed
and piles them in huge drifts to the
north and east of the point of origin.
The wind erosion excavates basins,
the fiat floors of which may be 10
to 80 feet below the surface of the
plain and so feet or more below the
tops of the dunes.
Basins of Moist Sands.
Nearly everywhere in the basin
floors moist sands are encountered
at depth of a few inches. Ordina-
rily sand erosion does not develop
fiat surfaces, but the f1atness of
these floors is manifestly caused by
the water table which limits the
depth to which the sand can erode.
The largest of the basins from
which the sands are blown is a
boggy lake bed at the south end of
the dune area, but many Of the
smaller flat floored depressions are
scattered through the area. The size
of the depression apparently af-
fects the height of the sand piles
built up to the lee of it.
Hills and mountains surrounding
the TularoSa basin contain gypsum,
and it is evident that some of the
deposit is brought from this source
by surface waters that feed it to the
large natural evaporation pan at the
south end of the sands. Whether
the source is the deeply buried beds
or the visible deposits In the noun
tains, the processes of evaporation,
crumbling, and drifting with the
wind are the same. The end product
is invariably beautiful, white, win
moved, and clean.
The picture afforded in this eX-
panse of white sand is unlike any
thing known. The white environ
ment has produced notable effect
upon the limited animal life of the
sands, and biologists look to this
natural laboratory for possible an
swers to questions bearing upon
adaptation. Botanists long ago
turned to the White Sands as field
in which to study the responses of
plants to unusual physical influences.
In places large cottonwood trees
nearly covered up with sand live
strange existence, producing roots
where upper branches once grew.
When the sand drifts and exposes
their modified anatomy, they still
stand, amazing specimens, with
roots interspersed with dead
branches along trunks much
changed as a result of long burial.
Disinterred specimens of the
yucca are to be seen that have
struggled in an effort to keep their
heads above the shifting sands until
their stems have elongated to some
thirty feet.