Box 15, Folder 5: Geographical Notes - Dells

1

Sauk County (August 1873)

Limestone - not the Lower Magnesian, but a layer in the Potsdam sandstone is found on the slope of the hill in the SE 1/4 of Sec 2 T 10 R 4 E - with sandstone both above and below -

Also East of Mr. Newman's, SE1/4 12 - 10 - 4 -

[pen sketch]

where sandstone forms both Creek Spring Sandstone

Shale

the bottom + top of the hill Limestone

Honey

with a layer of sandy limestone Sandslone [Sandstone]

surmounted by shale, belween [between]. A fine spring gushes out from the shaly layer. From the top of this hill, as from many others there is an extended view of the surrounding hills +valleys, including the "Negro Head" +c

Other springs are found where this shaly layer appears on sections 1 + 2

It is probable that this limestone + shale occurs in many other places concealed by the surface soil.

Quartzite occurs at the Falls SE1/4 35-11 -4 having the same characteristics as at the Narrows +c. It is surrounded by sandstone.

Conglomerate appears in the face of a hill below the falls

2

At the "Upper Narrows" of the Baraboo river near the ^Ableman rail road station, the rocks show five different epochs or ages

1st - The dark reddish* quartzite which is the oldest of the series. It has a varying dip towards the north, and is cut by cleavage plains in different directions. It forms high steep bluffs with irregular columnar projections Ripple marks on the nearly perpendicular faces of some of these rocks, plainly show that the strata have been tilled [tilted] up from the horizontal position.

2d - A portion of this quartzite after it had been hardened and metamorphosed has been broken into angular fragments of all sizes and well characlevized [characterized] forms, and then cemented into a breccia. The cement is usually quartz - with talc. Some cavitees [cavities] are lined with small crystals of quartz This breccia lies between layers of quartzite, which show no indications of any difference of age except their super= =position, nor would it be possible to determine when the brecciation occurred

* The grey [colls?] when seen in mass is owing to the lichens that cover nearly the whole surface of these rocks

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[pen sketch]

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3

1 2 1

Section "Upper Narrows" of the Baraboo + the high ground opposite

3 - Resting against the quartzite at each end of the Narrows is Potsdam Sandstone; on the north side exactly like that of the Dells of the Wisconsin river at Kilbourn Their wavy irregular thin layers give them a peculiar readily recognized character, and this portion of the Potsdam series may be distinguished by the name of the Kilbourn sandstone. It is probably among ^the oldest of this series. At one place it has been worn into irregular surfaces as if formerly washed by the current of a river. The sandstone abutting against the quartzite at the south end of the section is more regularly stratified + consists more exclusively of quartz grains.

4

4th Resting non = conformably upon this Kilbourn Sandstone + upon the quartzite is a layer of Conglomerate consisting of rounded masses + pebbles of the quartzite firmly cemented by sand. Near the quartzite the pebbles are large - often a foot or more in diameter, but they become smaller as the distance from the quartzite beds increases. Much of the conglomerate is made up of closely aggregated pebbles ; but the proportion of pebbles to the sand diminishes as we leave the quartzite until it gradually assumes the character of sandstone above. The occurrence of trilobites + brachiopods both in the lower sandstone + in the conglomerate show that they betong [belong] to the same (Potsdam) age.

The pebbles [counts?] entirely of quartzite & must have resulted from some geological aclion [action] upon the islands of quartzite when it formed the shore of the Potsdam Sea

5

5th Above the conglomerate but mostly back from the face of the narrows the overlying sandstone occurs - still of the Potsdam age, doubtless a continuation of the deposit that, mingled with the pebbles, constitute the conglomerate

[pen sketch]

A portion of the gorge constituting the narrows is occupied with a deposit of yellow marly Earth [disposed?] in layors [layers] indicating a lacustrine origin. It corresponds with what has been compared with the Loess of the Rhine - It is not "drift" of the glacial period; & has no boulders or pebbles of a northern origin The Upper Narrows are outside of the limits of the Boulder Drift.

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Mineral Paint is said to occur on the land of Godfry Kranz (SE 1/4 of SE1/4 29- 12- 4 E

Clay suitable for fire brick on land of Oscar Dixon NW of SW 1/4 of 16-12- 4 (Reedsburg) - This is a whitish slate, probably of Potsdam age + doublless [doubtless] too siliceous for the purpose indicated.