The Harrison times., 1901-02-09
reader can favor either the ascending
or descending order. as may appear
most convenient

reader can favor either the ascending
or descending order, as may appear
most convenient.
Directly everything the Crystalline
Base is what Professors Swallow
and Broadhead, in their Geological
Reports on Missouri, have recogniz-
ed and termed the 4th Magnetism
Limestone of supposed Lower Silur-
ian age. The late Professor Gala
her, in his Report (Vol. 13) has as
signed all of the stratihed rocks be-
low Swallow S No. 3 Sandstone, Gal
laher's Roubidoux) to the Cambrian
formation. 1t is not at all likely
this member is exposed at the sur
face anywhere in Northern Arkan-
sas, and even the Magnetism next
above, Swallows 3rd (Gallaher's
2nd) in all probability is completely
hidden. except in the deepest ravines
or where extraordinary uplifts or
faults occurred. In order, therefore.
to supply a geological column that
will, in a general way exDlain the
whole series of stratifed rocks that
IN all probability exist in Northern
Arkansas, we are obliged to borrow
from the Missouri Reports until
coming to the 2nd Magnetism, ac-
cording to Swallow, which is the
limestone that forms the country
rock throughout nearly the whole of
Marion, and a good portion of
Boone county. Although there can
be no doubt of the existence of this
Cambrian series or 4th Magnetism
Limestone in Arkansas, considerable
allowance should be made tor vari-
alton in thickness and, while some,
of the individual members might in
some instances be omitted, others
entirely different from the ones given
might also enter.
Since Prof. Gallaher went far more
into detail respecting this portion of
the geological record, we will profit
by his instruction and name the var
ious members accordingly. Prof.
Swallow recognized the 4th Magnes-
ian Limestone, or Cambrian, in
Camden Co, Mo-, and estima ted it's
thickness there at 800 to 400
feet. He describes it as presenting a
more permanent and uniform lithol-
ogical character than any Of the Mag
/ nesian iinesteHes; color. gTa y isn bnff,
coarse grained and containing a few
cavities filled with less indurated sill
cious matter
Professor Gallaher says of the Bas-
al Sandstone shat it sis obviously
the first Paleozoic sedimenitary rock
in Missouri and the first member of
our geological record. 1t varies
greatly in Theological character as
well as in thickness. n the central
zones of valleys. however, and in the
| central areas of wide basins, where
in it may be considered in its normal
conditions, it is pure white quartz
ose sandrock, not materially unlike
any one of the Infusorial sandstones
OF the Calciferous group. 1t vari~-
in thickness, between one--;--n and
one hundred feet, but its average
thickness is fifty feet In the vicin-
itv of Mine La Motto it has been
penetrated to a depth of $50 feet
without reaching bottom.
1t is highly silicious rock and
made up of very coarse grains that
show scarcely any wear or rounding
from the action of running water
In some cases there is very little ce
menting matter and it has the ap
pearance of a coarse and angular
loose sand, while in other instances
- is cemented together as though
ssed by the in6ltration and alb
<w, of mineral solutions from
ar =. 1t pres.sents at times varie
ty of colors, including Serhite. black
deep, dark green, yellow. PINK ana /
almost red.
Next aboye this Basal Sandstone |
comes Magnetism limestone, term
ed by miners, the white Lead" 1t |
is the principal horizon which is fur
nishing the valuable bodies of dis
seminated lead now being mined in
Southeastern Missouri. This also is
a very coarse grained and Crystal
line rock. 1t varies in thickness, be-
ing, at Mine La Motto from 20 inch
es to 20 feet, while at Flat River it
is 50 feet, at Doe Run SO to 80 feet.
and at the Hunter shaft, miles
east of Irondale. the disseminated
lead bearing rock is claimed to have
a maximum thickness of 100 feet.