St. Charles City Republican intelligencer. [volume] (St. Charles City [Charles City], Iowa) 1857-1861, 1859-05-12

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country. are quite heavily skirted
with timber. The larger portion oI
Mitchell and Floyd, as also of Worth
and Ccrro-Gordo counties, is drained
by the Cedar and its branches, OF
which Lime and Shellrock creeks are
the most important. These are all
beautiful and rapid streams, skirtcd
with timber and furnishing good wa,
ter-power at numerous points. There
are also many rock exposures in the
banks of these streams, although no
high bluffs occur, the lodges of rock
not usually exceeding ten or twenty
feet in height. The region between
the valleys of the streams is mostly
gently rolling timber, which is almost
exclusively confined to the edges of
the streams the soil is usually high
ly fertile. The settlements are chiefly
in the neighborhood of the rivers,
where timber, water-power, and build
ing-materials are abundant, and where
the fiourishing condition of most of
the towns, which have only been very
recently settled, attests the presence
of an industrious population. possessed
of unusual advantages Of position and
soil.
The larger portion of this extensive
region, which embraces over 5000
square miles, if we include in it Worth
and Cerro-Gordo counties, appears to
be chiefly underlaid by rocks of the
Hamilton group which, although diff
fering considerably in Theological
characters at various exposures, are
still characterized by the same fossils,
which have been collected in this
group at numerous points farther
south. The details of some of the
sections measured by Professor Hun
gerford are as follows:
In passing from Jacksonville to
Bradford, in Chickasaw county, dis
tance Of eighteen miles, across re-
gion drained by the three forks of the
Wapsipinicon, not "A single exposure
of rock was found. The whole dis
trict is one vast expanse of low level
prairie, excepting the tringes Of wood
land along the courses of the streams.
Near the east bank of the Cedar,
one and half miles below Bradford.
the annexed section was measured at
the quarry of the brothers Layton
Dark-gray thick shaly limestone
I feet.
Butfgrey crystalline limestone with
calcareous spar cavities-5 inches.
Light-grey, fine. grained limestone
inches.
Hard, dark-grey shaly limestone
8 inches.
Hard, ,dark-grey lmestone-7 inches.
UneXposed-2 feet.
Light, butf.grey lmestone-l ft. 8 in.
The limestones exposed at this quar-
ry are of medium purity, and mostly
quite hard : they are entirel y desti-
tute of fossils, SO far as observed.
Ia passing up the Cedar river to St.
Charles, on the west bank, the road
lies over a rolling prairie. In the
ridges limestones occur, as is shown
by the presence of occasional frag-
ments lying on the surface, or perhaps
here and there an imperfect exposure.
The beds, as observed, are mostly
shaly, and singulariy devoid of fossils.
An actual river section seems nsces-
sary to the determination of their rcla-
tions to each other.
On the Cedar, at st. Charles, there
is small opening in thin beds of hard,
buff.colored limestone. Under these
beds occurs thick-beGded, light-g
limestone, shading off into bufl.grcy :
it contains numerous cuncretions.
Both the upper and lower beds contain
few fossils, all of which are in a
very imperfect condition, so that only
one, at Atrypa reticaiaris, could be
made out. There were few frag-
ments of corals obtained here, which
are too poorly preserved to be dis
tinctly recognized.
The next section was taken at a
quarry three-fourths of mile above
ST Charles, on the west side of the
river. The beds are of very hard
limestone, which is mostly tine-grained
and rather brittle they vary in thick
ness from four inches to one foot and
the different layers resemble each 9th
cr SD much that they could hardly be
distinguished in hard specimens, es.
pecially as they are all equally unfos.
siliferous. The whole section exposed
is only nine feet above the dam at ST
Charles, of which two at the base are
concealed by detritus.
The courthouse at st. Charles is
built of this rock, which is a good ma
terial for building, although too brit.
tie to dress evenly and handsomely
The quarry is conveniently situated
for use, as the back-water from the
dam sets up as far as that, and allows
the blocks to be RATED down to the
town. The beds exposed at this point
are probably little higher in the Sc
ries than those of the section at ST
Charles but, as there is considera
BILE irrcgularity in the dip at this point
this could not be determined with Ger
tainity. At the quarry above tho
dam the dip was observed to be lSo
in direction S. 250 w.
On Lime creek one mile above Rock
ford, the annexed section was meas
ured:
Soil, &c., feet.
Decomposed limestone detritus witt
numerous fossils-25 feet.
Blue clay (foot of precipitous bluff
one-eighth Of mile from Lime creek
30 feet
i A gently inclining surface, mostl.
, unexposed, with buff and white stripe,
f limestone at the base-43 #. 10 in.
Unexposed-2 feet.
Dark colored. hard limestone-2 fl
i White, pure limestone with shal