STRANGE ROCK FORMATIONS--TABLE MOUNTAIN OF CALIFORNIA
There are many table mountains in
different parts of the world, but the one which I
am about to describe is interesting both from geological
and financial stand-points. The so-called Table
Mountain of California is a massive natural railway
embankment or colossal Chinese wall, extending through
several counties, but best studied in Tuolumne County.
The mountain is forty miles long,
from five hundred to eight hundred feet high, and
a quarter of a mile wide at the top. For the most
part the top is bare of vegetation and quite level,
though slanting slightly toward the south. In
places at the base of its precipitous sides, and sometimes
extending part way up, pine and other trees are found
This gigantic wall, broken through
in several places by flowing rivers, is nothing more
nor less than a mighty stream of congealed basaltic
lava called latite, which in prehistoric times, rushing
down the western flank of the high Sierras, usurped
the bed of an ancient river channel, drinking up the
waters and piling up its molten mass bank high.
The bed of the stream being filled
with lava, its waters not flowing through the gravel,
were forced to find other channels. The action
of the elements during subsequent ages has worn away
in great part the banks of the pliocène river
and eroded in places the solid slate rocks to the
depth of two thousand feet, leaving this sinuous wall
as a mute witness of the mighty forces of nature.
On account of the excessive hardness
and durability of this kind of basalt, this monumental
fortress will endure long after the corroding tooth
of time shall have crumbled to dust the royal pyramids
and their very memory shall have been lost in oblivion.
Some geologists think there were two
volcanic streams of lava, one succeeding the other
by an interval of thousands of years, the first covering
the auriferous gravel and the second quenching the
waters of a subsequent river which had forced a passageway
through the first flow of lava.
Scores of tunnels have been run into
the mountain to get at the gravel of this Pactolian
river. Millions of dollars of gold have been extracted
from its bed, and millions more await the tunnel, upraise,
and drift of the adventurous miner.
Beginning at the top of the mountain
and working downward, we find the order of materials
as follows: A cap of basalt from sixty to three
hundred feet thick, a bed of breccia of varying thickness,
two hundred feet of conglomerate andesitic sand (volcanic
ash of the miners), a bed of pipe-clay, and then auriferous
gravel resting on a bedrock of slate. In tapping
the ancient river-bed considerable water is encountered
flowing through the gravel. To get rid of this
water has been a problem of expense and annoyance
to the miner.
To measure the time that has passed
since this buried river rolled over golden sands staggers
the intellect. It is estimated that from one
hundred and fifty thousand to four hundred thousand
years must have elapsed.
This curiously formed mountain has
been likened to a monolithian serpent. Where
the Stanislaus River breaks abruptly through the mountain
the eye gazes in wonder from the crest down two thousand
feet to a seemingly tiny crowded stream below, rushing
madly on its way to the sea.
Many interesting remains of animals
have been found in the gravels under this mountain.
In running a tunnel under Table Mountain some years
ago, the miners came across a large mass of tallow
weighing about one hundred and fifty pounds, and in
proximity were the bones and tusks of a huge animal.
Many bones and tusks of the mammoth and mastodon, not
to mention the remains of other animals, have been
found in the ancient river-bed. Probably some
of these elephantine animals were sporting in the water
and dashing it over themselves when the stream of lava,
sweeping down, overwhelmed them, trying out the tallow
and preserving their skeletons for the wonderment
of civilized man.
At one place in the mountain the deep
roar of a waterfall is heard. At another, where
there is a deep break, is a series of passageways and
caves where the outlaw Murietta had his hiding-place.
In several places on the top of the mountain, by striking
the foot down hard, a hollow, reverberating sound
is heard. We give in his own words the account
of an explorer’s visit to the so-called
Boston tunnel which runs beneath Table Mountain:
“Hearing of a celebrated petrified
tree in the Boston tunnel, which runs under Table
Mountain, I determined if possible to see it and procure
some specimens. After considerable inquiry I found
a miner who said he knew where the tree was; that
the tunnel in which it was located had been abandoned
many years ago; that no persons had entered it for
years; that rocks were constantly falling, making
it exceedingly dangerous to enter, and that very likely
it was so clogged up with rocks that no one could
get to the tree. When I had expressed my great
desire to see this tree, and coaxed him, at length
he promised to take me to the tunnel to see its condition,
but said he would not promise to guide me into it.
“Having dressed ourselves in
overalls and jumpers, with candles and geological
hammers in hand we set out for our destination.
On approaching the tunnel my guide at once began to
throw stones into the bushes on either side of the
entrance. When asked why he threw the stones,
he replied that about the mouth of old tunnels rattlesnakes
are wont to resort to get out of the burning sun.
“Not finding any rattlers, we
proceeded down the incline to the mouth of the tunnel.
Finding the mouth not obstructed, and lighting our
candles, we entered. Sometimes crawling on our
hands and knees over fallen rock with scarcely a foot
of extra room above our heads, then stooping low,
then walking upright, again crawling between huge masses
of rock and earth, and crowding between slanting monoliths,
we made our way through the mud and water dripping
on us from the roof above.
“When part way in, the guide
hesitated and declared that we were taking our lives
in our hands if we went farther; that the five-ton
rock lying in front of our path had very recently
fallen from the roof, probably a week before, possibly
a day or only an hour before. Pointing to the
roof with his candle he said: ’Do you see
that piece of rock partly detached and ready to fall
at any moment?’
“Acknowledging the threatening
conditions, I urged: ’If not too dangerous,
I do wish that we might go on until we find the tree.’
“Said he: ’If you
promise not to strike any of these rocks with your
hammer, we will venture a little farther.’
“You may be assured that I not only promised,
“At this juncture, I must confess,
a peculiar sensation came over me when I thought of
the possibility of being buried alive or crushed to
death in this subterranean cavern, yet pride kept me
from showing the white feather.
“The guide, going ahead and
examining the walls and roof, called back to me in
a low voice, saying, ‘We are now safer.’
“Having traversed the main tunnel
for a distance of upward of eight hundred feet, and
carefully avoiding its branches, we finally came to
the object of our search. This tree, four feet
in diameter, of opalized wood, stands upright on the
left side of the tunnel. The lava had burned
off the bark and partly carbonized the outside part,
and then the whole had subsequently taken the form
of opal silica. There is a space of about four
inches between the tree and the surrounding lava.
“By raising the candles above
our heads we could look up the body of the tree some
thirty feet. When we had broken off some choice
specimens from the body of the tree with the hammer
we left this subterranean world. On emerging
from the tunnel the guide said: ’Thank God,
we again see the sunlight.’
“To which I replied: ‘Amen.’”