The state republican. (Jefferson City, Mo.) 1871-1896, 1895-11-14


ROCKS OF MISSOURI. II
In the report Of the Missouri Gee
logical Survey, which has just bed
issued by the State GeoIogist, DE
Charles r. Keyes, there il an import.
ant consideration Of the granite roc,rl
Of the state. n
Tho GRANTEES Of southeastern Mis-
souri, are Of unusual interest Ard
great commercial value, for tho rea4:
son that they arc the only orystallin1
rocks occurring in the Mississipp(
valley between Central Arkansas ard
Lake Superior, and between the Ap-
palschians and the Rocky Mountains,
The development Of these areas y
therefore of special Importance o3
account Of the wide extsnt of terri
soxy thsy I sxs eapehi . espdl1iH
e;
IN isstitutins = inyssadSatiiG 4
the quality, sdaptabiiity and sxails
bility Of the various rock masses, the
Missouri Geological Survey has be-.
gun to carry out the inquiry along
several different lines, the results Of
all Of which will be, when brought
Of the greatest Importance
as determining the comparative value
OF the rocks - coustructional mate
rial. When the work will have been
completed, - = part Of the compre-
hensive report on the building and
stones Of the state the
various rocks will not only have been
tested by ordinary engi-
neering methods, but modern petro-
graphical examination; that Is, ex-
animation In thin slices under the
will have been made.
Thus the microscopical character
and consequently the mineralogical
constitution will be determined with
great detail.
The FIRST results Of the general in
vestigations have Just been published
- o part Of volume 8 Of the reports
of tho Missouri Geological Survey.
It is . strictly Photographed study
with little direct reference to It's eco
nomic bearing, but It forms the foun-
dation upon which is now being
reared . structure of the greatest
popular interest and value. The til
tle Of the work is the "Crystslline
Rocks Of Missouri" and is the out
come Of researches conducted by DR..
Erasmus Haworth, now professor Of
inorganic geology In tho University
Of Kansas.
There are . number of points con-
csrning the rocks In question which.
aside from their economic import
ance, are Of unusual interest. To
begin with, the geographic distribu-
ton Of the massive crystallines pre-
sent certain peculiarities. They are
confined to the southeastern part Of
tho state, where they occur in irreg-
lar masses and isolated hills, extend.
ing over an area seventy miles
square, which is widely known a.
the Iron Mountain country. The
series consists Of GRANTEES and porph-
yries as the principal types, with sew
ersl varieties Of dark, trappean rocks
which are chiefly disbase, and which
occur in the form of dykes. All ara
very old, In fact, the most ancient
rocks exposed within the limits Of
the state. They are regarded a. ig-
neous In nature, and a. pre- Cambrian
In age. The nearest exposures Of
rocks Of Ike antiquity occur In
northern Wisconsin and Minnesots.
outcrops Of other crystalline masses
are found in central Arkansas, bui
all Of these are much younger, prob
ably cretaceous, and consequently
are In no way related to those oi
Missouri.
Tho approximate center Of the
crystalline district IL Pilot Knob.
For . distance of perhaps Q dozen
miles In all directions from this point
the massive crystallines form The
greater portion Of the surface rock;
while in an eastorly direction they
are practically continuous for moro
than twice - far. Beyond the lsrgs
central field the the exposures grad.
ually become less and less frequent.
To the north they do not reach much
beyond Bismarck. Northwsstward
they are found in Ste. Geneyisve
county, thirty miles from Pilot Knob.
On the east, hills OF aimilar rock ara
abundant - far as Castor Greek.
10 the south they stretch away in
large masses for many miles, with
occasional outcrops 90 far ss the
boundary line Of Butler county. To
the southwest they extend into
Shannon county, and perhaps even
beyond. They stretch out to the west
almost unbrokenly to the east fork
Of the Black river; while numerous
scattered hiils continue even beyond
the middle fork Of the same stream.
Towards the northwest similar rocks
occur ct short intervals - far q
Little Pilot Knob, in Washington
SSounk~