Box 13, Folder 4: Blue Drift Clay 1869

[July, 1869?]

Blue Drift Clay.

Along the shores of Lake Michigan in Wisconsin the hard, tough, blue clay forms the base of the drift formation, lying in many cases directly upon the polished + grooved surface of the rock. If there is any difference of age in the several parts of the drift, this must be ranked as the oldest - the primary drift. - At Racine the Quarries of limestone have been opened to a considerable Extent and show uplifts, accompanied by deep and narrow cracks or veins. Some of these are filled with this blue clay of the drift ; which may be regarded as another proof of the great age of this clay, for it was the first to find these crevices and fill them. It shows also that the crevices were open at the time when the deposit of clay was commenced. Is it probable that the drift period found the rocks in Wisconsin naked ? - a country whose surface was bare rocks, without a vestige of soil-or of vegetation? -

At Wauwatosa native copper is frequently found in similar crevices, and near the surface of the rock above. Its greater specific gravity would cause it to sink in the soft clay to be carried along near the bottom. These masses of copper often show signs of battering + even of scratches +c

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[July. 1869]

Drift.

In the County of Walworth. the drift . appears in great force, in some places so deep that the bottom has not been reached by the deepest wells. The upper layer or portion consists of a yellowish clay, mixed with usually small pebbles and some sand. The larger boulders though found in this clay. are rare. The pebbles consist of the usual varieties including hornblendic rocks, flint, limestone (Niagara) Bituminous shale, granite +c.-

Beneath this yellow clay the well digger often comes upon a layer of black mucky soil with compressed peaty matter and logs of wood, (coniferous) which in one case rests upon white shell marl, the shells being the same species as now inhabit the small fresh=water lakes in the same locality. This black soil is said to have been found at the depth of sixty feet. Wells have been sunk 120 feet without finding the underlying rock.

It is therefore modified drift or lacustrine deposit

On the SW 1/4 of Sec 24 [T?] 2 R 16 being the highest ground around a well was sunk in December 1868 to the depth of

*It was first discovered by the well-digger in the well who [th] left it to go up in the bucket with the clay; afterwords found by the boy upon emptying the bucket.

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fifty two feet, and when 44 feet deep an Indian arrow head of white flint [flint] was found in this yellow clay, among the pebbles

[pen sketch]

Outline showing the exact form and size of the Arrow head found in a well 4 miles east of Delavan Walworth County, Wisconsin, by Jonathan C. Church. this On the 16th day of July 1869 at Delavan [Delavan] whence I came went for the purpose of ascertaining the facts in regard to the discovery. It is of white flint + could not be distinguished from others frequently found on or near the surface of the ground. The evidence of its having been really found in the well appears conclusive - The ground being frozen + covered with snow at the time would seem to preclude the idea that it might have been accidentally associated with the earth thrown out. *It was discovered by a boy who was employed to empty the bucket as it was drawn from the well, who was also curious enough to gather other specimens, that attracted his attention by peculiarity of form or color.

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Drift

Coming Eastward on the railroad from La Crosse to Milwaukee we first meet the "drift" a little Eastward from Kilbourne City, forming at once considerable hills of gravel with boulders of various kinds of rock'. Among these are fragments of limestone having the [quartay?] druses characteristic of the "Lower Magnesian [Magnesian]" which is supposed to be the western equivalent of the "Calciferous Sandrock" of N. York. No fossils are here found.

A few miles further East, at Portage city, I found besides the lower Magnesian, fragments containing the fossils of the Buff Limestone. - which in the lead region lies between the Blue Limestone and the upper sandstone (Raphistoma lenticularis + Buthopteris [succuleus?])

Still further East boulders of still higher rocks are found until at the lake shore those of the Devonian age occur-the highest rocks yet known in the state

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Emery* found as a boulder in Minnesota indicates that this important mineral may hereafter be found in the interior of Wisconsin Emery given me by Prof L. J. Germain.

*Quartz only