The Richmond palladium., 1867-08-22
TIN MINES OF MISSOURI.
Interesting Report by Prof. J. w. FosteE.-
Geological Structure..First Discoveries
Of fTin-.Characteristics ofthe Tin Re gion.


In,ere.ting Report by Prof. J. w. Foster--
Of fTin--Characteristics ofthe Tin Re gion.
GEOLOGICAL srRUcrURs.
In Southeastern Missouri embracing the counties of
Iron, Reynolds and Madison, is tories of crystal
line rocks which were erupted, consolidated and
abradsd beforsthe dawn of the Sjurian epoch. They
consist of porphyrss, GRANTEES and quartsites, to-
gether with vast deposits of specular and magnetic
oxide of iron. There is remarkable absence of the
chlorits and alcoss states, and If except the quart
zites of other rocks which show distinct lines Of
bedding.
In the pre-existing depressions Of this primeyal
crust deposited the lower magnetism imestone1-
the great lead-bearing rock Of Missouri, some
hundred feet in thickness, which, slightly mstamor-
phossd in character and slightly disturbed in strait
ncation, envelopes these crystalline masses, the
waters Of the St. Lawrence envelope The Thousand
Islauds ..4sf as Rls sW srEt sssaf4r.t.
ths country were stripped of its detrital covering
and the observer sufficiently elevated to com
mand birdseye view Of its surface, he could count
thousand Of these crystalline islets rising through
the magnetism limestone in the depths of this old
Silurian They constitute the culminatng
points OF the region attaining elevation Of more
than thousand above the Mississippi river whose
course is about fifty miles TO the eastward These
FIRST DISCOVERIES OF TIN. x
Although for yssrs there have been vague rumors
of the existence of tin in this region yet DR. Albs-t
G. Koch-a name connected with some Of the most
brilliant discoveries in American Paleontology--be-
longs the msri, Of first having discovered the Of
tin the surface and Of having subsequently traced
them to u well defined system of veins He COM
msnced his explorations far back 1861 but
this debatabs ground during the great rebellion,
having been repeatedly swept over by the opposing
forces he compelled to suspend operations until
the present year. Blythe aid of A. O. Zane Esq, .,of
81. Louis, he furnished with to sume his
operations, which were attended with many difficult
ties by of detrital covering Of clay, for the
mostpart conceang the rocks; yet he has succeeded
in laying bare within the area Of square mile
less than odes, which Afforded in each instance
under the blow pipe distinct traces Of tim This
embraces parts of sections IA and 15 township 33
north, range east, in Madison county. sse@e4
As the statement 10 the existsncs of tin re-
cevet for the most part with extreme dstrust, and
in instances ith utter Incredibly, felt unwil
ling publish my opinion without first subecting the
gangues to the severest crucial experiments. 1
cordngly passed portion of them to my esteemed
friend Dr. Baney, Professor of Chemistry in the Rush
Medical College. who, although thus far confning his
analysis specimens, has found that they
dunn of silver. He has not gone into quanta:ive
analysis, but will do so other engagements
permit.
The veinstones, so far as examined by me, do not
exhibit the oxide of tin in crystalline form, but the
metal is finely difnsed. have, however, my pos
session q specimen obtained few miles distant,
where the crystals are of regular form and Of q
splendid lustre, difuse1 through gangue Of calc
spar and laumonite. One might search for q day
finding more beautiful cabinet specimen. This is
sample Of considerable quantity that thrown
out Of an excavation sixyears ago, and which OK
cited some neighborhood discussion asserting
that il was cobalt others that it magnetic oxide
of iron, but finally all concurrsd that it was
of no soonimcal value.
OF the existence of tic, therefore, in Missouri there
can be no doubt.
z CHAcrERtsrIcs TIE TIN REGION.
Picture to yourself valley about mile in width,
hemmed in by ridges of quartzite and porphyry, with
an isolated DOME Symmetrical in form, rising about
midway between the walls, with two small
circng its base, and you have the main fea-
lures of what has been christensd Tin Valley. The
intervening space is almost everywhere covered by
yellowish clay which, when penetrated to the depth
Of two or three feet. is found to rest . of
decomposed granite.
this region which deserve to be mnutsy described,
o. their anaogues DO found in other stannier
ors regions. Iual * festse ,ss
I. Porphyry-There are long lines OF porphyritic
rocks particularly observable At the Iron Mountain,
which traverse the country in the form Of immense
dykes. Ofa,Arm texsare. and having had the power
to resist alike the abrasion of the draft currents and
the weathering of atmospheric agents. they, have
been left in sharp and well defined ridges The color
Of the porphyry i of reddish brown, the texture
close hnd in composition il i fsdsp ashic rather than
hornblendic. ,g~ - s f
2. Qusrtxite-Ths is very hard close grained rock
Of dark gray color, and traversed by two or thres
distinct sysems of cleavage, that readily breaks
into forms Of great regularity 1t is in the base
Of Pilot Knob and far tvo-thirds of the distance up
it, summit exhibiting distinct lines Of bedding, and
Ike ths porpHyry, Il forms abruPt donss and rdess
Gssajet-Fhess tssksappesr in . dssemPosed
STATE, and bat decomposition extsnds 70 the grsatss
depth thus far psnstrstsd-ons shaf having rsashsd
to the depth Of twenty-five feet. Having no power
to resist decomposition abrasion, they are found