NORTHEASTERN WISCONSIN. 457 
The red clay here rises higher above the Lake than in the section, and was 
mingled with limestone gravel. It also capped the bluffs over the limestone, form- 
ing small knobs, from one hundred and fifty to two hundred feet above the Lake. 
On these knobs are traces of ancient earth-works, which are very common about 
Lake Winnebago. 
These cliffs extend northerly, at apparently the same elevation, to Clifton, which 
is at the north end of the Lake, thirty miles distant; but I was unable to give 
them any further examination. At Neenah, opposite Clifton, on the west shore, 
but little raised above its level, are quarries in low swells of the lime-rock. 
For several miles along the low country of the lowest shore, between Oshkosh 
and Neenah, this limestone is struck in sinking wells, after passing through a few 
feet of clay. It lies in thin, rough-bedded layers, is of a yellowish-gray colour, inclined 
to be argillaceous or marly; its fossils scarcely recognisable, except an Orthocera, 
about two and a half inches in diameter. There are also some undetermined spe- 
cies of Strophomena, Encrinites, and corals. The low ridges appear to result from. 
wrinkles in the upper layers, as if they had been pressed slightly together, at their 
edges. The lime which is made from this rock, is not very strong, but answers 
tolerably well for masonry; and the thin-bedded rock makes excellent stone for 
rough walls. 
At the “Grand Chute,” the head of which is ten or twelve feet below Lake 
Winnebago, the lime-rock is again visible, in thin, rough flags, and in thick, coarse- 
bedded layers, of various colours, varying from yellowish to bluish and whitish-gray. 
It is compact, or finely subcrystalline, with cavities, containing sulphuret of zinc. 
Its fossils are very indefinite, but apparently corals. The internal parts of the 
yellowish layers are blue, like the Cincinnati limestone. The dip apparently north- 
east, and very slight. 
At “Grand Kaukaulin,” pronounced by the French, Kok-a-lau; by the Indians, 
Kau-kon-nee (meaning ‘pickerel fishery’), about sixty-four feet above the Lake, is a 
thick-bedded lime-rock, with a magnesian aspect, dipping rapidly to the south, 
overlaid as usual by red clay. It has a yellowish-gray colour, is slightly crystalline, 
and has a few fossils. One of these was very well defined, but broke in getting it 
out; and another, of the same kind, obtained at Oak Orchard, was lost during the 
journey up the Oconto. I regarded it, from inspection, as the Trochus lenticularis of 
Murchison ; by Hall, called Plewrotomaria lenticularis, of the Trenton limestone: the 
same fossil was found by Dr. Owen in the blue and gray limestone of the Wis- 
consin River. There were fragments of Orthocera, that resemble the O. equalis 
of the Lorraine shales, and some well-preserved specimens of Pleurotomaria, the 
apertures excepted. They are one and a half to two inches long, with four and 
five whorls. 
At the lock pit at “Dupere” (a corruption of Des Péres), at the lake-level, the 
lime-rock is of a bluish-green cast, occasionally yellowish, in flags and thick-bedded 
strata, of a rough aspect. Here are very large Orthocera, six and eight inches 
across, but of no great length, with parasitic shells attached. I saw no fossils suffi- 
ciently well preserved to determine their species. In the limestone of Frankfort, 
Kentucky, which is by some regarded as equivalent to the Trenton, there are 
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