Loudon free press. (Loudon, Tenn.) 1852-1855, 1853-01-15
FALLS OF THE OHIo-HOW FORMED.

FALLS OF THE OHIO-HOW FORMED
We published recently an interesting sketch
of the lecture of Prof SILLINAN on the Falls O
Niagara We find in the Louisville Journal g
notice of recent lecture by DIR. YANDELL, also
delivered before the National History Society
| upon the Falls of the Ohio, at Louisville The
geology of the valley of the Ohio was dwelt on
the lecturer presenting some striking facts in its
history as shown by geological evidence. The
valley forms the principal break in the original
table land which once extended over a vast area
of country, at height still indicated by the
SUBMITS on the hills on each side of the river
! The falls are composed of ledges of limestone,
and belong to the Devonian group OF rocks
The Journal says-'sIhe river has laid bare an
ancient coral reef not surpassed in extent and
the variety and beauty of its fossils by any SINH
lar one in the world. The limestone is easily
decomposed and worn away by the water, so that
the corals, which are much harder and often
silicifed, are left projecting from the general
surface in bold relief and sometimes erect upon
their stems as if they were alive. We have
seen here Fdrosites more than yard in diam
eter with their honey-comb structure perfectly
! displayed. The delicately beautiful "chain CO.
ral' is found of similar extent, together with
several species of the cup-shaped Cyathopylia,
and these corals are interminged with masses
of the stems Of lily encrinites. So perfect is
the preservation Of these corals that no one but
geologist could distinguish them from the
recent corals of the West Indies yet so old
the fossils that are referabe to an era antece-
dent to the Alleghanies, the Alps, and the Pyra-
nees, nay, even to the time when by far the
greater part of the materials composing these
mountain chains were slowly elaborated be-
meath the ocean.'-Lyell Higher up are found
chambered shells 70! thoceras,) some of which
reach the enormous length of six feet. great
vauety OF encrlnlteS or stone lilies, and the
somewhat less numerous remains of the highest
forms of animal life of that PERIOD the triObates
animals somewhat resembling crabs, and occa-
sonaly the teeth of the cartilaginous fishes,
which were analogous to sharks. Beautiful
specimens of these fossils were exhibited by
DR.. Yandell, selected from his extensive cabi
net" The Journal closes its account of the
wonders revealed by science and the wear of
water in the valley of the Ohio, by giving the
conclusion of the lecture in nearly the words of
Dir. Yandell:- Cyeceldad Ohio Herald.
There was period when there were no rapids
here and no river. In ages intellectually far
back wide sea occupied the place where we
now dwell. From its tranquil waters were de-
posted those Sedimentary rocks TO the depth of
many thousand feet. Up from It's frequent
shoals grew forests of beautiful zOophytes, un-
folding their many tinted petals to the sun
There swarmed myriads of shell-fsh, whose re-
mains form the compact limestone from which
the edifces of our city are built. Among these
febler races sported the curious trilobites, the
terror, it may be- of this ancient ocean. Then
hOurished the orchoceras, whose many-chamber-
ed shell enabled it to float or sink at pleasure
while its powerful prehensie organs, arranged
ike fingers around its mouth, made it the rival
of the trilobite. Towards the close of the era
in which our limestone deposits took place,
creature Of a new and nobler form was intro
duced-an animal with brain and organs of
sense lodged in cavities of distinct head
The fish at length appeared, not such as those
which now inhabit our river, but one of uncouth
form, with broad scales and skeleton of carti-
lage instead of bone. From the bottom of the
shadows encrnites, the lilies of the ocean, rose
by long flexible stems which swayed to the mo-
ton Of the waves, or enabled the animal to
reach the Shell-fsh and trilobiteS which consti-
tuted its prey.
The current of the ocean at length took an
other direction and came loaded with another
sediment. The lime eminently favorable to life
was replaced by clay from which animals derive
no nourishment. The pellucid water was load
ed with mud, and its myriad inhabitants ceased
to exist During this period the black slate was
deposited in which we find only few struggling
shells, the remnants of the race which preceded
them. After time the sediment was exhaust
ed, and the ocean bore down fine sand the
detritus of older rocks, which forms the sand
stone of the knobs and rests upon the slate
And when again the ocean became charged with
lime, without which the hard parts of animals
cannot be formed, aquatic creatures once more
peopled the waters. Then there was an abun-
dance of criDnoids and shell-fsh, and many new
species of fish. At length the deposits ceased,
and as the continent began gradually to rise the
ocean currents commenced the work of cenuda
ton, following out valleys and tranporting ma
terals to form distant and newer rocks. When
the land finally emerged the wearing action of
water still continued The rivulets gathered
from the rains of a thousand hills, united to
form the Ohio and cut its broad channel. Thus
were formed the falls of the Ohio, from whose
exposed rocks and clustering myriads Of organic
remains, we are able to read their history in
times so far remote from the origin of man.