Grant County herald. [volume] (Lancaster, Wis.) 1850-1968, 1878-02-21

of hill unexposed. l. quarry, 2. Curved
out to the N. w. or. of Sec. 7, T. Z
Il. 4, E., where they present the same
appearances. In each of these local
tiles, the thickness of the OVERLAPPING
Lower Magnetism does not exceed
100 feet.
From the results of certain expert
ments instituted upon the shales de.
signated in the section as No. A, we
are inclined to think they would make
a tolerable quality of hydraulic lime,
although they are not sufficiently
quick-setting to make good hydraulic
| cement.
1t will be seen from inspection OF
the foregoing section, that no sand
stone is included in the Lower Mag.
nesian formation which extends to b.
Some biologists, however, place the
line dividing the formations between
the beds numbered nine and ten un-
der B in the section, p. 66e, thus in
Guiding the Dicellocephalus shales and
limestones, as we'll as the upper bed
of sandstone, in the Lower Magnetism
formation, and beginning the Pots
dam with the bed numbered ten. If
this arrangement were adopted, the
Lower Magnetism would sum up as
follows: Limestone above the sand
stone bed No. 8 of the section, full
thickness, ESQ feet; sandstone As feet;
shales and limestone, 81 feet, making
total of $50 feet, which is much
greater than has heretofore been at
tributed to the formation. On the
whole, it has seemed best, on paleon.
tological grounds, for the sake of per-
spicl,ity, and to avoid confusion in
comparison with other reports, to re-
spect the old landmarks of subdivis.
ion. especially as bed No. contains
the characteristic Potsdam fossils.
Pateontology. The fossil remains
Of this formation seem to be chiefly
confined to the calcareous strata and
areillaceous shales, described under
numbers 4 and of the foregoing Sec
ton, the most productive being those
which Immediately overlie the lime
stone quarry rock. All the quarries
from Black Earth to Boscobel were
examined, and, in all, more or less
specimens were found. The remains
consist chiefly of Lingula aurora and
Dtcellocephalus Minnesotensis, the for
mer being quite small, and usually
having the she'll remaining some
times, however, the shells have been
ground up so that only a few frag-
ments are found, disseminated through
the shales. The trilobites are seldom
or never found entire, but usually the
cephalic portion, the pygidium, or
still smaller fragments The various
sandstone beds of the Potsdam are
usually unfossiliferous. The upper
bed of sandstone seldom contain any,
thing but Scotithus, which in some To-
calities is very numerous. This fossil
is also frequently found in all the
sandstone beds.
LOWER MAGNESIUM LIMESTONE.
Geographical Boundaries South of
the Wisconsin river and north of the
main watershed, it occupies tract of
land lying about the heads of all the
smaller tributary streams. although
seldom found so far back as their
springs Passing down any Of the
streams, such as Otter creek or Mill
creek, we gradually pass below its
surface; and its outcrops are seen
gradually higher in the hills, until. on
reaching the Wisconsin river, it forms
the cap of all the bluffs from Sank
City to Boscobel, usually appearing
IN bold and rugged cliffs, lending a
very picturesque effect to the scenery
of the river. 1t forms also the valley
of the Wisconsin for about four miles
above its mouth, and the valley of the
Mississippi as far south as Glen Ha.
ven, where it passes beneath the sur.
face. Passing south of the divide
which separates the waters which
flow into the Wisconsin from the Peca-
tonica, it is found in the branches of
the latter stream, as far north as the
north line of town in ranges 5 and
E. Proceeding westward, it is not
again encountered until the Platte and
Grant rivers are reached, where it is
found as the bedrock of those
streams, and in T. 5, r. 8, W., it
covers large portion of the town
ship.
In Green county, there is but one
exposure of the formation. 1t is in
the valley of the Sugar river, about
three miles above Broadhead. 1t COM
mences a short distance north of the
center of Sec. Is, T. 2, r. 9, E.,
where it has a width Of abou: half a
mile. In passing into town three, it
widens to nearly two miles. 1t then
becomes narrower, attains its greatest
elevation above the river at Albany,
and finally disappears beneath the
surface of the river about mile aud
half above that village.
Lithological characteristics. After
passing through the transition beds
separating it from the Potsdam sand.
stone, it assumes all the qualities char.