The Manitowoc tribune. [volume] (Manitowoc, Wis.) 1866-1878, 1868-01-23
NIAGARA FALLS.
Signs OF an Eearly Breaking Down OF
the Horse Shoe Ledge--A Stupend9eS
Change In the Cataract Ab0atJo W.

periodot time is likely to be consumed by
the Falls of Niagara in wearing their way
up the bed of Niagara River, past iona
wanda ana Black Rock, until they be-
come at ;B,,Haio the Fails Of: lake Erie,
has been raised aHeW of late by 80 me ~ye-
markable gus observed in the rapids
above Horse Shoe Fall, (which. are thought
to forebode an early downfall. of the rocks
forming that magnificent cataract. For
more than a year past, some watchful
residents Of the vicinity have marked a
peculiar motion of the rapids at a point
something less than half mile above
the apex of the horse shoe, in the chan
mel which the greatest body of water de-
seconds, and this motion has been of a
character to give rise to the suspicion
that a breach had been made by tbs cur
rent through the soft shale strata under
lying the limestone thai forms the pres
ent ledge of the Fails. Recently the APP
pearaaee of the rapids, at the point indi
Gated, has undergone marked change,
| and so exactly in confirmation of the
| theory stated, that those watching it do
| not doubt the speedy doom of the IA
| nous Horse Shoe Cataract If the lime
stone ledge, over which the river now
| falls, Is. as supposed, In course Of being
undermined by a subterranean stream,
! breaking through as far back as nearly
| half mile, OF course the consequences,
! inevitable and liable to ensue at any mo-
/ tnent, must be an immense breaking away
CT the face OF the cataract, changing it,
| whole form and appearance-perhap
converting the perpendicular fall into a
| shooting rapid, down a steep decline.
Some observers at the Fails anticipate
| this grand catastrophe at an early day
| In confirmation of these opinions, we find
| it stated in the Hamilton {Ontario) Times
| that within a few weeks past, s.Dr. j.
| n. Osborne, of Chippewa, has noted a
| marked and constant change in the mo-
| ton of the rapids at the point indicated
and tits also reported that indications are
| discovered of the pouring of subterra-
| mean stream into The gulf below the Falls.
which the absence of the mist, it is tho t
would reveal beyond doubt. > The
same paper remarks that a gentleman
from the Fails with whom it has convers-
| ed fully believes that the days of the
Great Horse Shoe are numbered.
If it be the fact that this grand catac-
| lysm is soon to occur, biologists viii only
| be able to account for it by the stlpposi
ton Of great fracture or assure in the
southward dipping bed of limestone over
the outcropping edge of which .he river
falls. Prof Halls elaborate survey of
the geology of the Niagara river region,
made in 1912, showed that, at the pres
ent site of the falls, sheets of hard lime
stone rock, of the formation known as
the Niagara limestone, cover the surface
Of the country and form the edge Of the
,at fn ho IL NJ Iaf l,@,
and ninety feet. Under this, extending
to the foot of the fall, are the shaly lay
ers Cf the same formation. All these
strata Slope downward, against the chr
rent of the 7icer, at the rate of about
twenty i've feet to the mile, aud in the
rapids above the fail the upperlnost hay
ers of the n iagara limestone succeed, one
stratum above another. till about fifty
feet more is added to the thickness OF the
formation, when all disappear beneath
the outer-oiilng edges of the next serie-
above, which is that Of the shales and
| marls of the Onondaga salt group. We
see, therefore. that both above and below
| the hard limestone there are soft shac
formations, easily to be cut by a rapid
| current; but the lower of these shale
| beds can only be reached and the lime
stone undermined by fracture in the
linestsne itself. 1t is very possiblethat
such a assure exists at the point where
| the changed motion of theF rapids has
| been observed, and that through it the
river has found its way to the underlying
shales and cut a subterranean passage
Should the undermined ledge of the
Horse Shoe give way, the Falls will per-
haps reccde at one step a greater distance
| than they have been borne back by the
wearing of two. or three centuries. Sir
VIM. Lyell estimates the average reces
sion IN recent periods o-have been about
"a toota year. Il is certain that consd-
cradle change in the situation of the Falls
| has taken place since Father Hennepin
rudeiy isketehed his view in 1878; for IN
| that sketch We have exhibiteda third fall
| from the Canadian side toward the East,
across the line of the main fall and caus-
ed by great rock that turned the divid
ed current in this direction In l $50 this
feature had already disappeared when
Kahn, the, Swedish naturalist, visited
the place. ~ 81 <ra3 81 81
1t is probable that the rate of recession
since the waters Of Niagara river first be
gan to cut out the gorge above Lewiston,
| has varied greatly at different periods, az
the formation Of the river bed has varied
| From the present site of the Falls, the
strata above described gradually rise to-
ward Lake Ontario to higher levels, till,
along the great terrace, the Gaping is of
the lower 20 feet IF the Niagara limestone
below which the shaly strata form the
next SO feet of the steep slope; next APP
pears succession Of zcalcareous LAYERS,
shaes and sandstcGes belonging success
lively to the Clinton and Medina forma-
tions. Through these piles of strata the
river has worked It's way back, receding
probably most rapidly where, as in the
present position, the lower portion Of the
| cutting was composed of soft beds, which
being followed out let down the harder
strata above, and less rapidly where the
strata near the base were hard sand
stones
1t was the opinion of Prof Hall, in his
report, that the effect of continued recess
sion must be 10 gradually diminish the
height of the Falls. both by the rising OF
| the bed of the river at their base aud by
| the Slope of the massive Gmestoneto a
lower level. The thin beddcd limestone
above being swept off, the succeeding
| shales and maTls of the Ononlaga group
must Immediately follow. and the Falls
he thought, may become almost station
AIRY, when their base Is at the base of the
massive sandstone, and their upper line
IS as now, over its upper edge. This
Prot. Hall thought likely to be the case
after further recession of about two
miles. and the height of the fall must Their
be reduced to about eighty feet.
In 1918 and in 1928. great fragments Of
rock fell at the Falls, with conclusion
which SHOOK the whole country around az
by an earthquake If our citizens are