The Saint Paul globe. (St. Paul, Minn.) 1896-1905, 1897-02-28

criptiOn Of the bed rocks Of this city:
The white and soft St. Peter sandstone,
about $50 feet thick, beginning below the
river level, and the gray and hard everything
Trenton limestone, about 90 feet thick, form
the bluffs Of the river valley in st. Paul.
The first OF these names was given to the
sandstone by the pioneer geoiog-st, David
Dale Owen, from his examination of it about
fifty years ago at the mouth OF the Minnesota
river then commonly called st. Peters riv-
err. In the bluffs there, at Mendoza and
Fort Smelling, as in his city, the sandstone
reaches a height of about 100 feet above the
river. The Trenton limestone and the i'm
mediately everything Trenton shales receive
their names from Trenton Falls. N. Y, on
account Of the close relationship of the fossil
faunas embedded in the sediments of the
very ancient Silurian ocean there and here.
This ocean stretched across ell the inter
vening area during very long period, which
is estimated by Dana, Walcott and others
to have been between thirty million and fifty
million years ago. Both before and since
the silurian era the duration of geologic time
has been almost inconceivably long.
THE first thirty feet Of the Trenton series
is the most heavy bedded and richly FOSSIL
ferrous limestone which is worked by many
quarries in st. Paul and N nneapols. Shales
Of greenish gray or of blush and leaden color,
also containing abundant fossils, with occa-
sional layers of limestone from a few in
ches to a few feet thick, form the upper
continuation of this series, and are exposed
to an observed height of about seventy live
each side of the river at distance of one
to two miles up the valley from the st. Paul
union depot. The maximum thickness of the
Trenton shales known in this city is revealed
by their outcrcp at the intersection Of Car
roll street with Dale and Kent streets, where
they rise in a low ridge about twenty five
feet above the fiat drift gravel and sand of
Tire surrounding plateau. At the house of J.
b. CLANCY, on Rondo street. the highest part
of this outcrop of shaies. overain by only
one to two feet of glacial drift, reaches a
height of 945 feet above the sea, or about
145 feet above their base in the neighbor;ng
valley bluffs and 262 feet above the low water
level of the Mississippi river.
Across the ten miles from The center Of
st. Paul to the center of Minneapolis tie
Trenton limestone beneath the shales and
the outlying drift deposits, extends with al
most perfect horizontally, and also south
ward to Fort Smelling; but toward the north
nation and the st. Peter sandstone rise
slightly, not more than a few feet to the
mile. SO that tie next underlying Lower
Magnetism or ShaEopee limestone comes into
view In the bluffs Of the st. Crox Missis-
sppi and Minnesota rivers. with still lower
formations, as described in the reports of the
Minnesota geological survey.
Volume H. OF the final reports Of this
survey has a chapter of thirty pages on the
geology of Ramsey county including ST. Paul,
with a map by Prof. Wincheil the state
geologist. In the third volume, published in
two parts, the fossils Of Minnesota are de-
Summing up the total number CT fossil spe-
cies found in the lower Silurian strata of the
Upper Mississippi region, including our dis
trict, Prof. Winchell credits our Trenton
series with 81 species Of brachiopods, 55
lamel1ibranchs (bivalve shells of the class
including modern oysters and clams), 50 gas
tripods (univalve shells including modern
snails), IL cephaiopcds Including several spe-
cies of Orthoceras from one of which cast
of it's interior cavity is conspcuously seen
in the accompanying illustration, and 20
trilobites (whose modern descendant Is the
odd horseshoe crab, common on our Atlantic
COAST.
When it is considered that the vast
ness Of the past duration of existence,
will no doubt be duplicated in the
never ending future ages to come, NOR
tai conception is too limited to predict
the consequences now only foreshadow-
ed by the flight of time
Then, instead Of the fossiliferous de-
posits of the silurian period, the bur-
led ruins Of an ancient st. Paul, will
be the nearest beneath an existing
surface, and the last existing life, like
the first, will be in the depths Of
the sea- Emergence will be followed
by a gradual obliteration and final dis
appearance. Dust to the living forms,
4 d the living forms to dust
B.