Lawrence democrat. (Lawrenceburg, Tenn.) 1884-1925, 1890-08-22
AN AGATE BRIDGE.
Some OF tho Wonderful Things In Chalce-
dony Park, Arizona.

dony Park, Arizona.
Among the great American wonders
is the silicified forest known as Chalce-
dony Park, situated eight miles south
of Corrizio, station on the Atlantic 81
Pacific railroad, in Apache County,
Arizona. The country formation is sand
stone on volcanic ash, and the trees are
exposed in gulches and basins where the
water has worn the sandstone away, or
are buried beneath the sandstone, their
ends protruding from between the for
nations. The locality was noticed in
1858 by the Pacific railroad exploring
survey. The jasper and agate generally
replaced the cell walls and fbers, and
the transparent quartz filled the cells
and interstices, especially whore the
structure was broken down by decay.
These cell centers and cavities pro-
duced conditions favorable not only for
the deposition Of silica as quartz, but
also for the formation of the drusy crys-
tallina cavities OF quartz and amethyst
thstso increase the beauty Of the ma
terial.
There is every evidence to show that
the trees grew beside some inland sea.
After falling they became water-logged,
and during decomposition the cell struc-
tNre OF the wood was entirely replaced
by the silica from the sandstone in the
walls surrounding this great inland sea.
Major John w. Powell, who has visited
all these regions, says: ''The wood con-
sisted of logs water-rolled before burial,
and are now gradually weathering out
of their matrix. The inclosing rock is
sandstone and cretaceous shale of the
series known as Jura-trias, and lying
Immediately above the Chinarump.
Agatized wood containing much semi
opal has been formed in California land
possibly in Arizona) under volcanic de-
posits, but the wood in question is not
associated with volcanic material; its
matrix is sedimentary."
The red and yellow coloring matter is
| derived from the oxide of iron in the
sandstone, which is red, and the black
may be due to partial carbonization or
to oxide of manganese. The bark in
nearly every case has been decayed be-
fore silicification, and even part of the
other layers of the tree is often gone,
but the difference between the oxidation
on the surface and inside is that the sur
face to the depth of half an inch is SC
altered and changed that it has the APP
pearance of bark, and is generally sup
posed to be such.
A phenomenon perhaps unparalleled
and the most remarkable feature of the
park is natural bridge formed by q
tree of agatized wood spanning canon
As feet in width. In addition to the
span fully fifty feet of the tree rest on
one side, making 1t visible for length
of over 100 feet Both ends of the tree
are imbedded in the sandstone. 1t aver
ages 81 feet in diameter, feet at the
thickest part, and at the smallest
Where the bark does not adhere the
characteristic colors Of jasper and agate
are seen. Although the wood is beauti
full to the naked eye microscope IL
needed to reveal its greatest charms
not only does the glass enhance the
brilliancy of its colors, but it renders
visible the structure, which has beer
perfectly observed, even to the forms o
minute cells, and is more beautiful nov
than before the transformation.
DR.. P. HI. Dudley examined micro
scopically some sections Of this WOOD
and found that part of it, at least, be
longs to the genus Araucaria, one spe
cies of which, Araucaria excelsa, thu
Norfolk Island pine of the South Pa
cific Ocean, according to the same au
thority, grows to height Of 100 to 20
feet Other portions were found to re
semble our red cedar, Juniperus Vir
giniana, when grown in the extreme
South. The cell structure Of some o
the wood indicates growth in mild
uniform climate, the annual rings bein,
marked by only one, two, three or NOR
slightly smaller hexagonal or rounded
not tabular cells, as is usually the case
The name of "Chinarump" has bee
suggested for this material by Majo
John M. Powell, this being the India
name for the substance. These trees
according to one of the Indian myths
were believed to be the bolts OF the ar
rows used by their god. 1t has been ex
tensively used by them in making spea
and arrow points.