The Corvallis gazette. [volume] (Corvallis, Or.) 1862-1899, 1885-10-16
RESOURCES OF BENTON COUNTY.


going to prove not only beneficial to
trade but interesting to the scientist
OR those of curious turn, in this. by
the excavations the workmanship OF
nature is exposed in such a manner
that we can take practical advan tage
OF its revealings, or, be satisfied with
viewing what is presented by it's up
heaval. There is a curious bit of coun-
try rounding Keyes hill, and under
and beyond Cardwell hill to the open
country about the Newtons S and Bain's
properties. Through this section are
"A number of knolls rounding or oblong;
their contour is smooth and graceful
and covered with a reddish clay loan
with a good stand of grass, giving at
once the impression that they were so
formed or placed without much effort
or violence. 1t is true that hereabouts
as we pass over the public road hard
iron stone boulders are quite numerous
and might suggest the character of the
knolls, but till the cutting through
them by the railroad their true con
struction was unknown.
Selecting one knoll (near Lilly's) for
our purpose. There is at this point
exposed the manner of uplift, or the
cause of these rounded knolls in that
vicinity. They are of igneous con-
struction, and, while they are thus,
there is side by side in the same uplift
two distinct characters of rock though
they must have been made from the
same material. One is Basalt and the
other IA Porphyritic Trackyte. The
first is strongly columnar, the latter in
rounded masses; the basalt is hard,
tough and homogeneous; the trackyte
is fragmentary, of different material
cemented together, hard, yet friable,
and much of it crumbles in the hand.
The latter is the cause of the knobs,
that is, coming up from the deep in its
shaft the molten rock instead of finding
an easy outlet in the earth's crust, finds
an easier bed in the soft clays or shales
in lower portion of the recent forma
ton thereabouts prevailing, thus eleva-
ting the earth's surface the height OF
its own imbedded thickness.
But the point of interest in this
matter and the reason for this corl.nu-
nication centers in portion Of this
Trackyte rock as follows: 1t is made
up of pieces of shale and other material
cemented together, also thick and thin
veins of felspar, sometimes resembling
fine net work in it's black ground.
Among the rocks which make up this
porphyritic mass are pieces of deep
black, brilliant, sometimes as jes, hav-
ing the appearance of camel coal. In
fracture it is conchoidal; to the eye and
hand it is hard, but under the file this
portion of the rock is as soft as soap
stone. Its powder is brownish and
grey. 1t crumbles somewhat in the
hand coal like never losing its lustre,
but after rain or exposure it takes on
greenish film covering most of it.
Dr. T. V. Hayden in geological dis
cription of the Yellowstone country,
same age as ours, makes the following
statement as to 4 point under observa-
ton: ''These basalts fracture readily
into small fragments, and the debris
resemble pile of dull anthl acite coal. >
Now as all the rock in this trackyte is
brought up from its bed and metamor-
phosed and that all, though originally
widely different, are now made similar
at least at distance to the eye, yet
under close observation differ very
much as we'll in hardness, fracture and
lustre. The question here forcing
itself upon us is this: May not this
which resembles coal metamorphosed
have been coal in its natural bed and
before the uplift Of igneous matter?
If this is so, then the coal fields of
Benton county must be extended to
to this portion of the county. 1t may
be added here that the colors and
materials in the clay, would justify
such conclusion. j. r.