St. Charles City Republican intelligencer. [volume] (St. Charles City [Charles City], Iowa) 1857-1861, 1859-09-01

EXTRACTS FROM HALLS GEOLOGICAL SURVEY.
Modern Geology is indebted for it.
rapid advances, and the certainty will
which its determinations are made a
different and distant points in the scd
lmcntary foSSiIiicrous strata, mainly
to Pat@Gmtology The careful stud,
Of the rock formations has shown thai
certain groups Of beds or strata which
lie one above another may be idcnti
fled hy the fossil remains which they
contain or, in other words, the beds
of limestone, sandstone, shalc, etc
have each in their turn, while in the
state Of sand and mud, formed the bee
Of IN ancient ocean, in which the thci
living forms have been inbcdded, and
are still preserved in the solid rocky
masses. The refinement to which
this study has been carried enables
us TO distinguish, hy a few fossil
forms, the relative age of certain beds
of rock to other strata which have
been elsewhere studied and rs all
experience has proved that the order
of sequence is everywhere essentially Y
the same, though certain beds may
hc absent or others intrrcalatCd, yet
the relative position OF known beds is
never reversed. We are able 10y this
means to determine at once the rcla-
tiuuS of all formations which come un.
der examination, to all others in the
known geological series. We have
thus n means everywhere at hand to
determine not only the relations Of the
rocks under examination to other simi-
lar or identical formations, but also
their relations to rocks Of known
economical value, or to those contain
ing materials of similar Importance
as coal iron ore, etc, without consum-
ing the time which would otherwise
be necessary in every new locality TO
determine the order and relations of
the entire set of strata and their min
cral contents.
This principle, in it's application, is
carrying out only that which any good
observer would do to limited extent
without geological knowledge for
if, after examining a limestone over
the area of q township or a county,
he should find it everywhere marked
by certain characters, and the final re-
suit proved it only valuable as lime.
stone, and containing 10 other ccono-
mical product, he would conclude that
the same rock, when identified at a
distance of ten miles, would possess
the same characters. Should this
limestone, in the area already exam
med, have resting upon 1t n sandstone
or shalc with coal, he would naturally
infer the same order, should he meet
the limestone above in any locality
not before examined.
Upon the same principle, geological
and archaeological knowledge ac.
quircd in one or many parts of the
country, as well as the results of OK
T2ricnce in other countries, are brought
to bear upon the Investigations Of any
portion heretofore uncxplorcd. Were
1t otherwise, the process of geological
examination would be slow and tcdi-
Gus, and the results unsatisfactory.
The rocks of the PalmoHoic series,
or those constituting the different di-
visions or groups, from the known
commencement of animal life to the
coal measures inclusive, constitute the
fundamental rock formations of mucI
the larger part Of the area Of tn,
State of Iowa.
The true order and sequence Of the
strata below the CarbouilcrQus torma
tons have been made known through
the Reports of the Ncw-lork Gcolugi-
cal Survey, more clearly and more in
detail than from any other course.
These results have been confirmed,
with many additional facts of great
Importance, from the Investigations
in the Canada Geological Survey
and the order Of sequence and nomcn-
claturc has been established from
Gaspc TO Lake Superior, and from
Ncw-lork to the Mississippi river.
The Reports of Pennsylvania and
Virginia have given a clear knowledge
of the structure of the coal measures,
and the sequence Of their different
members in the eastern part of the
great Appalachian coal field while
the Reports of Ohio, and more recent
ly of Kentucky, have shown CORE
spending sequence on tue western side
of tue same region. West OF the
Cincinnati axis, we know the coal
measures Of Michigan from the Re.
ports of DR.. Houghton those farthe,
west, from the Reports of DR.. Owen
on Iowa, Minnesota, etc and those
of Missouri, more in detail from the
Reports of Prof. Swallow.
The craboniferous limestones, lyins
beneath the coal measures, and form
ing so conspicuous a feature along tn,
Mississippi valley and throughout til,
west and southwest in the coal-meas
ure regions, arc scarcely rccognizabl,
on the east Of the Appalachian chain
or beneath the coal measures of Penn
sylvania, Ohio, Eastern Kentucky, an,
a large part of Virginia.
The great plateau of the Northwest
stretching from the Appalachian chair
westward to the slopes of the Rock,
Mountains, and limited on the nortt
by Lake Huron and Lake Superior
presents great simplicity of geolosi
cal structure. The entire sequence o
formations, from the Potsdam sand
stone to the coal measure inclusive
occupies the greater portion of thi
! arao and the slirht disturbances I,
which they have been subjected, an,
the tcnuity of the formations, hav
served only to make the succcssiv
beds more accessible to investigation
Towards the Rocky Mountains, tn
pal;eozoic rocks are ovcrlaid by tn
Crctaceous formation, which, in it
lower arenaccous members, stretche
from the northern limits OF the Unite
States territories to the Gulf of Mex
co, and throughout a great part [
this extent rests unconlormably npo