Crittenden press. [volume] (Marion, Ky.) 1879-1907, 1894-08-09
OUR MINERALS.
CONTINUED FROM PAGE THREE.)

valuable only when one or both wall
are limestone. The depth to which
the deposits extend depends upon
two conditions: Cd the thickness OF
the limestone formations through
which the assures pass: and (2) the
amount of displacement to which the
strata were subjected at the time of
faultering. The llmestones that
must counted as the principal source
of the metals In this region. are the
Princeton and St. Louis, having an
aggregate thickness of no less than
five hundred feet in this county.
Beneath these limestones the fOrma-
tons for hundred of feet would be
counted by drillers as mostly slate.
At the Columbia Mines the lime
stone forming the east wall may be
counted on as extending downward
ut least four hundred feet, when the
shaly beds Of the lower sub-carboni-
ferrous W ii lie encountered. This is
however not the end Of the entire
series will be met with again, but
this time on the west side of the
vein at the depth of four or five hun
dred feet. Hence the vein will have
a limestone wall, and therefore
should be productive, to a depth of
from eight to nine hundred feet. We
must not forget that the country
rock on each side of the vein was
once an unbroken series of strata,
and tfat limestone which may be al
the surface on one side occurs also
on the other, but at the depth cores
ponding to the amount of the down
throw. Essentially the same cOndl.
tons which have been described fol
the Columbia will be found to pre-
vail ut the Tabs, Franks and othel
mines.
The vast system of faulting tC
which the rocks of this county have
been subjected is well shown on the
accompanying map. Over twenty
distinct lines of fracture have been
determined, and It is certain that
others remain to be traced out and
still others, perhaps to be discovered.
Comparatively few::cf these fractures
are as yet known to be filled with
metaliferOus deposits, the majority
being recognized only by abrupt
breaks in the continuity of the rock
strata. Many of these breaks pass
through sandstone country, and
these, as may be expected from pre-
ceding remarks on the association of
the minerals with limestone. are not
likely to present anything but very
meager prospects at the surface. If
they contain metaliferous deposits at
al, and we know of no reason why
they should not, these probably
occur at depths beneath The surface
corresponding to the ositiOn of the
limestone beds. Al some points the
top of the Princeton limestone may
be three or four hundred feet below
the surface, as .Or instance on the
Columbia vein between the Ohio
river near Weston and the crossing
Of the Hurricane break near the
Springs. At others the depth may
be less than 100 feet. Still, in search
ing for mineral deposits the prospec-
tor will do well to follow the lines
Of fracture as laid down on the map,
since success is much more likely to
reward his efforts along those lines
than elsewhere. Valuable deposits
may be discovered at almost any
point on item, but experience teaches
that the chances for finding them at
the surface are by far the best where
limestone Occures on one or both
sides of the fault.
LEAD AND ZINC VEINS.
At least four veins that may be
styled as above occur in this county.
have not the time, nor is it uecvs-
'ary, to do more than merely men,
ion the chief characteristics of these.
The first and best known is the
Columbia vein. Its course is shown
IN the map. 1t has been opened at
several points, but at only one has
he shaft been sunk lower than forty
Get. This is at the main shaft of
he Columbia mines, sunk in or near
he axis of intersection of the Eureka |
md Columbia veins to the depth of |
80 feet. At the SO foot Level four
lrifts each from one to two hundred |
Ong, were run out on the two veins.
The workings at the mines, by
'age and Krausse of st. Louis. was
he first systematic attempt to devel-
pc the lead and z.nc deposits of the
Ounty with anything like the capital
to back such enterprises.
Inc work was, however, undertaken
t an unfortunate period in the his
Dry of mining, the great depression
n mining enterprises which set in
S77 and seriously affected The min
ng interests of the whole country,