The diamond drill. (Crystal Falls, Iron County, Mich.) 1887-1996, 1890-11-08
NATURAL BRIDGE OF AGATE.
some Of the Wonderful Things In ChAics-
dony Park. Arizona.

uOul INfk. nltutitu tlHnl mites SOutu
Of Corrizio. station on the Atlantic
aud Pacific railroad. in Apache Coun-
". Arizona. The country formation is
sandstone on volcanic ash, and the
trees are exposed in gulches and basins
where the water has worn the sand
stone away, or are buried beneath the
sandstone. their ends protuding from
between the formations. The locality
was noticed in 1853 by the Pacific rail-
roads exploring survey. The jasper
and agate generally replaced the cell
walls and ibers, and the transparent
quartz filled the cells and interstices,
especially where the structure was
broken down by decay. These cell
centers and cavities produced condi-
tions favorable not only for the deposit
ton of silica as quartz, but also for
the formation of the drusy crystalline
cavities of quartz and amethyst that so
increase the beauty of the material.
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
STRUCTURE of the wood was entirely re-
placed by the silica from the sandstone
In the walls surrounding this great
inland sea. Maj. John w. Powell. who
has visited all these. regions, says:
The wood consisted of logs water
rolled before burial aud are now
gradually weathering out OF their ma
trix. The inclosing rock Is sandstone
aud cretaceous shale OF the series
known rs Jura-trias. aud lying immedi-
ately above the Chinarump. Agatized
wood containing much semi-opai has
been formed In California (and possibly
in Arizona) under volcanic deposits, 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 OF
10 oxide OF manganese. The bark in
nearly every case has been decayed be-
fore siliciiication. 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
surface to the depth of half an inch is
SO altered and changed that it has the
appearance of bark, and is generally
supposed TO be such
There is every indication that the
deposit is of considerable depth. Over
the entire area trees lie scattered in
all conceivable positions aud in frag.
ments of all sizes, the broken sections
sometimes resembling a pile of cart
wheels. A tree 100 feet in length il
often found split into as many sections
of almost uniform length, presenting
the appearance of having been sawn
asunder for shingle-blocks by some
prehistoric forester or broken into
countless fragments. ranging from the
size OF small pebble to that of fair.
sized bowlder also fractured into per
feet shaped cubes as IL cut by a lapd-
ary. These multiplied fractures are
the result of alternate heat and cold.
produced by atmospheric changes act.
ing on the water in the assures OF the
tree.
A phenomenon perhaps unparalleled
and the most remarkable feature of the
park is natural bridge formed by o
tree of agatized wood spanning a canon
45 feet in width. In addition 10 the
span fully fifty feet of the tree rest on
one side. making IL visible for a length
Of over 100 feet. Both ends of the
tree are Embedded in the sandstone.
Ii averages l-2 feet in diameter. 4
feet at the thickest part, aud 3 at the
smallest. Where the bark does not
adhere the characteristic colors OF
jasper and agate are seen. Although
the wood Is beautiful TO the naked eye
microscope is needed To reveal its
greatest charms; not only does the
glass enhance the brilliancy of 10
colors, but IL renders visible the struc.
ture. which has been perfectly pre-
served even to the forms of minute cells.
anu - more DeautlfuI now than before
the transformation.
DIR. +. H. Dudley examined micro
scopically some sections Of this wood
and found that part of it, nj least, be-
longs to the genus Araucaria. one
species of which. Araucaria excelsa. the
Norfolk leland pine of the South Paci-
iic Ocean according TO the same author
ity. grows TO height of 100 TO 200
feet. Other portions we're found to re-
semble our red cedar. Juniperus Nir-
giniana. when grown In the extreme
South. The cell structure of some of
the WOou luul'htes RIoNth ih ~ Hit"'
uniform climate. the annual rings be-
T, ing marked by only one, two, three. or
more slightly smaller hcNagonal or
rounded. not tabular cells, as IS usual
ly the case. The name of 'Chinarump"
has been suggested for this material by
Maj. John w Powell. this being the
Indian name for the substance. These
trees, according to one of the Indian
myths, were believed TO be the bolts OF
the arrows used by their god. IL has
been extensively used by them In
making spear aud arrow points