Grant County herald. [volume] (Lancaster, Wis.) 1850-1968, 1878-03-07

There exists at Mineral Point, at an
elev alton of about fifty feet above the
upper surface of the Buff limestone.
or quarry rock, stratum of compact
limestone several feet in thickness.
which in color and texture closely re-.
sembles the lowest recognized Blue
limestone, and contains Sfrophomena
alternate. Lept9na sericea Bellerophon
oltofdtus, and some varieties of Orthis.
all in great profusion, and all of them
characteristic of the Blue limestone
below. The strata which separate
them are not exposed.
1t seems probable that this upper
stratum may correspond to No. 5 of
the preceding section; that Nos. 6
ana are the unexposed beds at Min
eral Point; and that Nos. and 9 of
the Darlington section represent the
Blne and Buff limesiones at Mineral
Point. The relations of the two prin.
cipal fossIllierous strata are not, how
ever, fully apparent in the Lead re-
gion, nor does the upper one seem to
be of constant occurrence. whereas
the lower one is universally recog
nized in Iowa, La Fayette and Grant
| counties.
East OF range three east, the pres
ence of the Blue limestone is nowhere
so clearly marked as west of this line.
1t is usually recognized by the out
cropping of quantity Of highly fos-
siliferous fragments, scattered through
the soil, having worn and beached
appearance. East of range three the
fossiliferous Blue limestone was not
found. 1t is replaced by yellowisb
limestone, containing but very few
fossils, and in all respects similar to
the Buff limestone. The thickness
between the Galena limestone and st.
Peters sandstone remains as usual,
| about fifty feet.
There are two exceptions to the
| foregoing general statement. Ii short
| distance south OF the center of Sec.
Is, L. l, K. 6, E., the Blue limestone
reappears in It's full thickness, with all
Its characteristic fossils, but only GOV.
ers small area of ground.
The second exception is situated in
the town of Mt. Pleasant, in Green
county, in the S. E or. of Sec. IL, Il.
3. II. z, E. 1t is known as the Mar.
| BILE Quarry, so named on account of
the fine polish which may be given to
the stone. The Blue limestone has
here the same thickness, both of the
thin and the thick beds, as in the
western part Of the Lead region. All
the. characteristic fossils are present
and in short, it presents all the usual
Theological appearances. It appears
to have been deposited in BASIN
shaped depression, as the top of the
st. Peters was found to be much lower
here than any where in the vicinity.
Although separated many miles from
any other outcrop of the Blue lime
stone, it is evident that it was depos-
tied under the same conditions, as in
other localities. 1t has been used
here for burning lime, of which it al
ways makes good article. Some
small pieces have been polished for
paper weights, and other small orna-
ments. 1t takes a high polish, equal
to marble, although large pieces can
not be obtained.
One other bed has been observed,
not mentioned in the descriptive Sec
ton. 1t is the line of demarkation
between the Buff limestone and St.
Peters sandstone. 1t consists of
greenish blue clay, usually from one
to two feet thick. The clay is very
finely laminated, and consists of argyll.
laceous and calcareous matter 1t
might be valuable as a mari, were
there not so much of the same con-
stituent parts in the surrounding soil,
as to make its application superfuous.
1t is not bed of invariable occur
renee, but it has been seen in so many
localities. over great extent of coun-
try, that it may be regarded as con-
stituent bed of the formation
Ores and Minerals The Blue and
Buff llmestones are the lowest in
which any ores are found in sufficient
quantities to repay mining. and the
northern and eastern parts of the re-
gion in the vicinity of Mineral Point,
Linden, Dodgeville. Highland, Gen.
terville, Miffiin, and the Crow Branch
Diggings are the most remunerative.
1t is not to be inferred from this that
the formation is barren in the south
ern and western parts, but rather that
it lies SO deep that it has not yet been
reached in the present system of
mining
Large bodies of Lead ore have from
time been taken from this formation,
but it seems to be more especially
productive of zinc, both as carbonate
and sulphuret. At present the zinc
furnished from the localities above
mentioned is chiefly derived from it.
Organic remains are found in the
greatest profusion, and in very fine
state of preservation, the rock in
many places being entirely composed
of them. In the Buff limestone they
usually occur as casts. Without par
ticularizing, reference is made to the
general list.
GALENA LIMESTONE.
In describing this formation the term s'Ga-
lena limestone" used in other reports, has
been adhered to in this, to prevent the con-
fusion arising from several names for the same
thing, although strictly speaking il is a dol
omitc.
Geographical Boundaries. This for
nation is by far the most important
in respect to lis metallic wealth of all
which we have to consider. In it are
contained all the mines of the south
ern and western parts OF the Lead re.
gion, and whenever mining has been
carried on in the underlying Trenton
limestones, lead is usually present in
the everything Galena
The Galena limestone is the prevail
ing surface rock in the Lead region.
Its northern outcrop conforms closely
to the main watershed, being parallel
to, and always within a few miles
| north of it. its surface area is given
as follows, for each range in the Lead
rpotnn.