Grant County herald. [volume] (Lancaster, Wis.) 1850-1968, 1878-01-31


which underlald it. This might at
first he accompanied
by slight recession
parallel to the line of aiE.lA
strike such move .SSaA -
ment, however, could -
not be OF long dura-
ton, but would be. ,
come less as the valley
became deeper; because any such
recession would necessitate the
removal of all the overIaylng for
nations. Finally the small streams
flowing across the strata would
cut their valley back from the river !;
the dividing ridge would recede, and
their sources would, from the position
of the strata, be in steep and precipi-
tous ravines. Such, IN brief, appears
to be the theory of the formation Of
streams in the Lead region. It's ap.
pllcation is easy, and would be as
follows
The Wisconsin river from Mazoma-
ME, to its mouth near Prairie lu
CHEN, is the most conspicuous exam
pie and illustration of the foregoing
remarks.
Although the surface of the coun-
try, In its present condition, does not
permit the accurate delineation Of the
former lines of outcrop, of the palezoic
formations; yet sufficient number
OF outllers remain, to show US that
they must once have covered the
country, far north of where they are
at present found. The existence of
Niagara limestone, in a thickness Of
about one hundred and forty feet at
the Platte Mounds, and probably the
full thickness of the formation at the
Blue Mounds, warrants us in suppos-
ing that the former outcrop of the IN
DERIVING Cincinnati group was at least
as far north as the present bed of the
Wisconsin river.
The valley now occupied by the
river. from Mazomanie to Rlua river
Is very nearly that of the present line
of strike of the Lower Silurian forma.
:ion, and, although from there the
strike of the lower members (of which
outliers still remain) appears to bear
rather more to the northward. yet,
observations on the dip of the Cincin-
natl group, in such occasional out
Tiers as remain, lead me to believe
that its original strike was approxi-
mately in Southwesterly direction,
from Blue river to the Mississippi.
Assuming, then, that the Cincinnati
group once had its northern outcrop
where the river now runs, or in line
parallel to it, in that vicinity, the sur
face waters would easily erode a
channe. in the soft and friable shales
which, to great extent, compose this
formation.
In fine, the whole process Of lorna.
ton previously described would take
place. On the north side it had, as
now, its principal tributary streams
the Kickapoo, Knapp creek, Eagle
river, Pine river and Bear creek, in
their present localities, and approx
mately their present length. On the
south of the river, however, the prin.
cipal watershed, already referred To-
was probably qaite near the river
] from which position it has receded tc
the place it now occupies. The Greer
river, Blue river, Otter, Mill and Blue
Mound creeks were small and insig
lnificant streams; which, by the grad
ual process of erosion, have increased
to their present size and length !; bu
even now, are small when compared
to the northern tributaries.
| A further effect was to shorten thu
Grant, Platte, and Pecatonica rivers
by the gradual southwesterly reces
sion Of the watershed, and the lower
ing of the latter by the denudation o
the Niagara limestone and Cincinnati
groups except in such localities Al
were protected by superior hardness
of some part of the formation, as il
the case Of the Blue Mounds.
The result of the denudation ha
been to divide the country into TIVE
parts, each differing widely from th,
other in its Typographical features
The streams flowing southwark from
the watershed have eroded the coun
try into gently undulating slopes. Thi
is probably due to the direction of thu
streams conforming in measure Il
the dip of the strata. Abrupt cliff
and steep ravines are the exception
and not the rule, never being found il
the immediate neighborhood of TIL
watershed, but rather confined to tn
small lateral branches. On the othe
hand, to the north of the watershed
the panorama of bluffs and precipi
tous ravines is almost mountainous il
its aspect. In fact, nothing can b
more striking than the contrast which
presents itself, from certain points Of
the divide, in looking from north I,
south In nearly all of the ravine
leading northward, the fall of the frs
. quarter of mile is not less than on
hundred feet; and, in general, it j
. true of the streams flowing northward
that three.q quarters of the fall take
place in the first quarter of the dis
, lance from their sources to thei
mouth.
1t seems not improbable that thes
, sudden declivities are due to tn
streams flowing over the edges of th
E strata, rather than lengthwise alon
their dip. Again, the streams fiowinI
to the southwark become compare
r lively sluggish in their course, as 500
e as they cease to be brooks. The
: have usually soft muddy bottom
r while those tributary to the Wiscon