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The finds described in this preliminary report represent skeletal material brought to the surface during dredging operations carried on at the West Des Moines plant of the Concrete Materials Company.1 The gravel pit is located in the SE Y4 of Sec. 15, T. 78 N., R. 25 W. on the floodplain of the Raccoon River, about five air miles above its confluence with the Des Moines. The valley wall on the north side of the Raccoon in this locality marks the maximum advance of Cary ice. The area south of the river is underlain by Kansan drift. The nature of the dredging operation, which extends to a depth of thirty-five feet, leaves much to be desired from the stratigraphic point of view. Most of the smaller teeth and bones, up to about ten inches in length, pass through the rotor of the pump and travel almost a quarter of a mile through a sixteen-inch discharge pipe where they are then dumped onto a screen. Naturally, this treatment is rather damaging to the more fragile specimens. The larger pieces, such as horns and skulls, are brought to the surface by an endless cutting chain which operates ahead of the pump.

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Proceedings of the Iowa Academy of Science





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© Copyright 1953 by the Iowa Academy of Science, Inc.



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