p.4

[continuation of article by I. A. Lapham, LL.D., State Geologist.]

GEOLOGY 19

[first column]

1st, A hardpan or unstratified boulder clay,
resting directly upon the smoothed and
striated rock-surface, very hard and tough,
and destitute of fossils. This is the original
deposit under the great glacier, a thousand
feet or more in depth, which once crept slowly
but surely over the surface; -- 2d, Beds of
sand and gravel separated from the hardpan
by the action of running water after the glaciers
began to melt away; and, 3d, Beds of
fine clay also separated from the hardpan at
the same time, but deposited in the comparatively
still water of the numerous great
lakes that then existed. This action of rivers
and lakes in assorting the materials of the
Drift is continued, though upon a much
smaller scale, to the present day.

The hardpan affords firm banks for our
lakes, and is the dread of well-diggers: the
gravel and sand are useful in road-making
and for mortar; and the clay-beds afford the
material for our white or cream colored
brick.

After this glacial period, when the ice had
retired, vegetation was spread over the land,
and animals of various kinds began to appear.
Among these were some now entirely
extinct, including the fossil elephant (mammoth)
and the mastodon. During this time
trunks of trees became buried in the new deposits
now often dug up from wells &c. The
great amount of rain-fall filled the valleys
with large rivers carrying away the looser
materials on the surface but leaving the heavier
boulders perched upon the surface, as if
they had been dropped from an iceberg.

[second column]

These strong currents probably were the
means of forming many of the ridges and
hillocks that now diversify the surface of the
ground.

It is now impossible to know what was the
condition of the surface of the state and what
were the plants and animals, just previous
to this glacial epoch, for all traces of them
were effaced by the rasping and grinding effects
of the moving ice.

Valleys were filled up and hills cut down;
great basins were scooped out to form the
beds of the future lakes.

When the ice was withdrawn the whole
surface was covered with drift.

It still remains to be accounted for that in
the lead-region in this state there is almost a
total absence of the Drift phenomena.

Pre-historic Man in Wisconsin.

A race of people once occupied our soil of
whom very little is known except what can
be gathered from their works and a few fragments
of their skeletons. With his introduction
geological history properly ends; and it
becomes important to know whether he was,
or not, cotemporary with the mammoth and
mastodon.

The indications now are that they were
quite different in many respects from the
modern Indians, though these may be their
descendants. In habits they were similar [similar] to
other savage peoples -- using the bow, and an
arrow tipped with flint, to secure their game
or punish their enemies.

He made use of native copper (which he
brought from Lake Superior, or found in the

[third column]

glacial drift) in making his arrow heads,
knives, chisels, axes &c., though it is doubtful
whether he had the skill to mould this
metal into form. His implements of unpolished
stone and of hammered copper, are now
found buried many feet in the earth; thus indicating
the lapse of many ages since his
time.

But perhaps the most striking peculiarity
of the Pre-history man of Wisconsin, was his

[black and white illustration]

habit of throwing up mounds of
earth in the form of animals and
of man. For what purpose these
were erected can now, of course,
be only an object of conjecture.
That they had some significance
seems quite evident.

We here give a carefully prepared
figure of this pre-historic
man and one of the animals as
represented in the mounds. They
each have a total length of one
hundred and twenty-five feet; the
former in Sauk County, was surveyed
by Mr. Wm. H. Canfield; the latter

[black and white illustration]

near Cassville, Grant County, surveyed by
Mr. Moses Strong.

Milwaukee, July, 1874