The Iowa patriot. [volume] (Burlington [Iowa]) 1839-1839, 1839-07-04
n Written for the Patriot.
n BURLINGTON, To- July, 1889.

In former letter j alluueu W ZIG StU'
illogical structure of the land of this terrific.
ny. i will now give some account as fal
as am able, which, however, from sew
eral causes will not be complete, Of its ge'
illogical formation and agricultural char
acter.
Near the summit Of the bluffs which
stated to be 100 feet or more above the
river, but underlying the soil few feet,
small fragments Of white soft flint, as
called here, though, as think, in union
with calcareous stone, first appear to In
dictate the group of earths to which it be-
longs. These are numerous, particularly
at this place: from which the Indians ma
med it Shokokon, that is, flint; and the
early American visitors, perhaps merely
translating the Indian appellation, called
lit Flint Hills Immediately beneath this
collection of fragments, and forming the
upper strata Of the ledge Of rock, are five
or six alternate layers of sandstone and
fossil limestone, the depth of the whole
being IL or is inches. This is feature
of great interest. One hundred feet or
upwards above the usual level of the river
| at the present time this collection of fossil
shells and polypi are found so numerous
as to form almost wholly, sometimes it
seems entirely the layer, in the manner of
the lumachelle or Carynthian marble.
The upper stratum of this series is fossil
lime or sandstone, being almost entirely
composed of shells so that it is difficult
to discern the kind of stone, if in fact
there be any intermingled. One of the
layers near the centre of this series, the
third or fourth from the top, is entirely
shell, the layer being from two to three
inches thick. The shells are all of one
kind; baculae, in this, as also in the up
per layer. In other parts encrinites oc-
cur frequently. These are found chiefly
in the fragments of white flint OVERLAPPING
the ledge. In other portions of the stone
but chiefly in detached fragments, not in
position, have found a very great varie-
ty of shells, among which the scollop is
very frequent, conspicuous, and i'll perfect
form and preservation, as are also many
of the others. / have an argillaceous or
marlous schist, about s inches square and
three or four in thickness, which | found
on the river edge containing many hun
dreds and including many varieties of
which only the scollop is known to me.
1t is divided into four plates by three
seams, each plate beautifully studded with
its share Of all the varieties. Both the
baculae and encrinites are I think marine,
and if | mistake not are considered by ge-
ologists as now extinct on the earth.
Thus, if J. am right in the superstition,
(ifnot you will readily correct it) the sea
has at some time covered this country to
the depth Of 100 feet or more above the
river level: but at all events it has been
submerged to that depth by a body of wa
ter, salt or fresh.
Next to this, below it in the series is
very brittle sand stone in several thin lay
ers, the whole being from 6 to - inches.
A hard grey fossil sandstone in layers va
riously thick comes next. The shells in
this formation are the same as in the up
per series. Below this is very hard
cinnamon or russell grey stone, similar to
the hard pudding, which | take to be
greywacke. Next to this is interposeda
reddish brown clay loan intersected with
fbrous roots. Then follows another stra
tum Of greywacke. This is succeeded
by white military oflithic limestone in
a stratum about Is inches thick, which is
quarried, burned and used for plaster,
Below this is blue limestone of the
thickness Of two feet or more, bed of
clay being interposed between it and the
white. This brings us down about Is
feet below the surface of the ledge: and
not having seen the ground opened be-
You'd this depth, | can say nothing ofwhat
lies below. Enough is discovered to
mark it as the lower secondary formation.
This formation would not be considered
very favorable to agriculture. But this
lower secondary earth is covered with
soil of much later formation: it may be
a diluvian or even a post-diluvian. The
prairie is fine black earth which seems
~. Ia thu oo1o IF tho 1unto,.o