St. Charles City Republican intelligencer. [volume] (St. Charles City [Charles City], Iowa) 1857-1861, 1858-09-16
Scientific.
From the Marion, (lini


the subject of Geology, and, TO pf'hS
myself within the compass OF a news
paper article. | shall necessarily have
to be brief and general.
Our local Geology does not present
hat rich variety and grandeur which
is displayed in a mountainous region,
where the more powerful agencies of
nature have been at work, crystalizing
the rocks, upturning the strata, and
throwing up mountain ridges from
the great cauldron of melted matter
below. The agencies that have been
at work here were nor uniform and
regular in their action, and consc-
q%uently our rocks lie but little dis
turbed from the position in which
they were first deposited, and the
fossil remains they contain are re-
markably well preserved. So COM
plete is their condition that they are
classified and named like living
species, and where they lived and
died, there they seem to have been
buried, in the comparatively still
waters of some vast bay or ocean.
The corals and shells found in our
rocks are those belonging only to
salt waters, and hence our whole Mis-
sissippi basin must have been a long
time beneath the ocean,. Probably
what is now the Gulf of Mexico, once
extended up over this whole area, and
has been gradually reccding to its
present limits. ..
The waters of such a vast gulf
would be pcopIcd with myriad inhabi-
tants of the sea, and be continually
making its deposits of sand and shells
as it was reccding, and, hence
we would expect to find the older
rocks to the north, and the newest to
the south, which we find actually to
be the case. The North rose first
from the gulf, and air and frost were
wearing away it's materials and the
rivers were carrying it down to help
form new rocks farther south.
The Oldest rocks in Iowa are in its
North Eastern portion, and though
they appear so nearly horizontal, yet
they all have a general dip to the
Soath West, and hence those rocks,
which we find up there, run far be.
meath us here, and coming from there
in this direction, you are rising con
sinually higher and higher in the Sc
ries of rocks, though you may not DC
ascending so much from an actual
level. Each of these formations has
received a distinctive name, and is
known by its peculiar character and
fossils, as well as position.
The Oldest formation is a sandstone,
and extends but little in Iowa, but
runs north into Minnesota and Wis
consin. Coming South you pass over
several formations of stone before you
come to the great lead bearing lime
stone at Dubuque, which is there two
hundred and fifty feet in thickness.
This rock is remarkable for its cavi.
ties, pores and assures, thus making
it we'll adapted to become a lead-bear'
ing rock, as the mineral finds an easy
entrance. This formation extends
over into Wisconsin and Illinois, ant
back into Iowa, so as to cover a larg'
area of country, and it has proved it
self to be one of the richest mineral re
gions in the Uuited States. In one
year this region produced thirty mil
lions Of pounds lead, and three mil
lions of pounds were taken from a
single spot, not exceeding fifty yards
square. This rock, dipping as the
others do to the South West, passes
beneath the river at Bellevue, ane
when we have come to the Cedar
Valley, we have risen to the rocks Of
the Devonian period, or the age Of
fishes, as it is called, and which lie
lust below the Coal Measures. Passing
on to the South West we 500 come
to the great Coal Basin, which extends
up into the interior of Iowa, covering
over a large portion Of her surface.
This County, then, is an older for.
mation than the coal period, and its
principal wealth lies in the richness OF
its soil, and the abundant facilities for
developing its resources through the
convenient intcrspersing of the timber
with the prairie, and the excellence
and general distribution of its build
ing stone and water power. The Mag
nesian and Arenaceous limestone OF
this County are and will be of great
value to it's inhabitants as a building
stone, from the regularity Of its layers,
the uniformity of it's character, and
the ease with which it may be quar-
ried and cut. They have been but
little developed as yet, and this value
is not fully known. They exist at va
rious points along the Wapsipinicon
and Cedar rivers, and the Arenaceous
has a large development nea the
mouth Of Crow creek. Coal is some"
times found in basins below its true
formation, as at Iowa City and neal
Palo in this County, and other suclI
basins may exist, but they are always
of limited extent, and no dependence
q be placed upon them. Lead has
also been found in our Blue limestone,
but the occurrences are rare, and in
small quantities, and the character o.
the rock is not such as to indicate it,
existence to any considerable extent
Though coal, lead and iron are found
as occasional specimens in different
parts of our County, yet the proba
bilities Of this being found to any
considerable extent are too few to al
low us to cherish very enlarged ideas
of our mineral wealth in that direc
ton.
There are many interesting facts il
regard to our surface Geology which
would like to present, had | spac,
and time, but all are acquainted will
the wealth of the surface soil practi
cally and scientifically. To the geolo
gist and enquiring mind, there ar
presented few more interesting sui
jccts for examination and study, tina.
the origin Of our prairies.
would like now to present some c
the objects of a Geological Survc,
that its value and Importance NAV,
nnssihle. be better understood