276 IOWA ACADEMY OF SCIENCES. 



Number 4 is a bed of loose sand, in which the layers of 

 finer grained material alternating with those of coarser 

 texture indicate a deposit along the bed of a stream in 

 which the strength of the current was variable. This sand 

 bed contains no trace of calcium carbonate throughout its 

 entire thickness. It was probably laid down by the waters 

 which resulted from the melting of the Kansan ice. 



Number 3 is a thick bed of clay, which bears numerous 

 pebbles and bowlders of various sizes. Many of the lighter 

 colored bowlders have partially decayed, and are so rotten 

 that they can be broken apart with the hands. For a 

 depth of four feet from the top the material has a some- 

 what reddish appearance. This color gradually changes 

 with the depth through yellow and gray to the bluish color 

 of the main body of clay. In the upper portion are several 

 pockets and lentils of rather fine-grained sand. The bed 

 is cut by numerous joints and cracks into prismatic and 

 irregularly shaped blocks and fragments. It is calcareous 

 throughout, hydrochloric acid producing vigorous efferves- 

 cence at the very top, immediately below the layer of 

 sand, as well as in every portion of its depth. 



Number 2 is a layer very different in character from 

 that which overlies it, or from that which is found below\ 

 It is dark brown in color and is largely composed of more 

 or less perfectly decayed vegetable matter mixed with a 

 soil which contains a considerable amount of sand. Near 

 the upper portion of this layer may be found a few f?-ag- 

 ments of wood and bits of roots and darker colored patches 

 of carbonaceous material. The bed contains no trace of 

 calcareous matter. It forms a conspicuous band eighteen 

 to twenty-four inches in thickness, which is exposed at 

 this horizon for a distance of forty rods. 



Number I is a bed of drift w^hich resembles in many 

 respects Number 3 above. Many of the pebbles and 

 bowlders which it carries are beautifully polished and stri- 

 ated. In the lower portion it is bluish gray in color, but 

 to a depth of three or four feet from the top the clay 

 has a slightly reddish tinge. This red color, however, is 

 not so marked as in the oxidized surface materials of the 



