Mineral Point weekly tribune. (Mineral Point, Wis.) 1859-1868, 1860-01-03
The Lead Region of the Northwest
No. 1.

In the third of our articles of the Lead Region,
we have given our readers survey of the ge-
osraphical situation of the latter, ami shall now
pass over, to the beginning of description
about the formation of the lower earth and
mountain layers, which We in due time accord
inc /, proportion of the materials TO be received,
shall endeavor to give as special as possible
The foundation of the named Lead Region
consists principally of Dolomite. stone when
its main ingredient representsa mixture OF lime
stone a maenesia The Biologists OF America
discern three kinds of this analgamation, VIZ
!. The N5aqara D2lomite. giassy-slnilar TO
sandstone appearing knd-which rock appears
in collosai LAYERS, at Niagara and thereiroin re-
ceiyed this name. The magnesia IS predomin-
ant in il against the calcarous earth, but less
rich in putrfactlon In this Niagara formation
- the lead in our region most concentrated, ana
+, !, the most caves occur, rs tn Is pre-emIn-
emily the ca.e in the neighborgood OF Dubuque.
where in such caves millions Of pounds OF ie-d
ore have been found One of the most interest
/ mo caves Is the one discovered some years ago
! by a certain LEvEy Of Duhuque-the explicit
description of which v-t shall furnish IN later
article
> THE GqEcaa Dolonlac SO called because 1t
rfedominates in the vicinity of Gdlena; 1t con-
taips more limestone than magnesia. and Is rlch
/ in putrifactions of shelIs-yet some occur, al
/ though less numerous, Of fishes. These rocks
are pre- Dominant east Of the Mississippi, while
the D,Ionrit occurs most on the west side OF the
stream. Yet the Galena Dolomite contains caves
/ in which considerable layers of mineral have
been found the more particular description OF
which shall appear IN successive articles to De
publjshe,i bv US In general the mineral N
this f,s,il-rock is more dispersed than eoneeA-
trated. the most formidable (miueral) lead yet
discovered. is that near Linden, Iowa County,
J Wisconsin.
i g. The blue Limestone, so called from us
particular color it occurs. invariably, between
the first enumerated, IN depth OF from ~ 10
/ 100 feet. projects, however, often far above the
surface .e the ground, and IS much used as
durable building rock TIE layers OF It seldom
ax,eel the thickness of Q feet, while the Nj
a.,ara and Galena D,ioul'e Is found in blooks-of
collossoI dimensions. Tie quarries Of tue blue
Limestone occur IN very regular lines, and out OF
if building stones Of almost every desired length
aad breadth can be obtained Ia tins po!oi1ite
tie most Interesting petrIiactons occur
IN all OF these three different species Of stone
within our Lead Region, the mineral ores are
struck partly IN fiat layers, partly N detached
masses, in caves aud pockets. and are frequent
ly accompanied by pyriies Of Iron aud Black
lack. Be.ilcs the lead ore however, copper and
iron ores are found, to which we shall reier IN
future
The riches Of the lead ore in this region, IS
according to facts elicited. 50 immeasurably
greal. thai against it. all what the deep mining
in Germany has produced, IS left far IN NE
shade. But the result gained here, until now
are exclusively the fruits of superficial. more
or less ignorant and without following the SCI
enee Of mining-undertakin digging-and to a
deptl-to the real foundation Of the mineral lay
ers not solitary shaft has been sunk. because
heretofore towards the surface, more Temnner-
a.inc body has been found. The Dolornit strikes
down TO an average depth of 100 feet. and until
this depth all rock consists Of 50 called (hori-
, zontaD strata or layers. The foundation Of the
Dnlomite whose range incllnes from North to
South. consis-s Of sandstone, rs shown By geo.
lnrical mediation. The latter have been shown
IN the State Of Iowa, BY JONES Hall, aud in
. Wisconsin, IN % aud IS, by James g. FerciTal,
and still later by Prof :. Danieis and these
as well a. the works OF owen. frruish remark
able IN uteresting results
These geographical researches IL iowa and
Illinois. have however shown, that the lover
strata Of Donali,e, consist very often of blue
: Limestone. after which only the ssadFock fol-
: lows. down to which. according to the conrnu-
m!catiou impaired TO rs. only on , places in the
I ,vh,Ie Lead Region shafts have been sunk down
ve shall later recur 20 this Ai;ef The ssRdrock
the "a called lower raagnesil lines one follows,
and al last the sandstone. and the thickness oi
! these LAYERS have. according 70 Perelvals Geo.
loelcal Report, the following average tilasn-
siuus:
The uprer ulagnesIa limestone 2l0 ieet.( above
ana below the surfacc oI the earth , the blue
lime zad sandstone 100 feet. and the lower
rnavne.la lineStaue 220 feet. The thickness o
) the lower sandstone j. comprehen-lbly not a.
vet aScertaiued. The details out Of tne repor
now b.f5re us. in regard 70 ore mining we shaI
: specially explain IL future article. aad furns
a. he .ame lilue interesting dates,