154 B. SHIMEK PLEISTOCENE OF SIOUX FALLS AND VICINITY 



Two loesses also appear southwest of Sioux Falls, as along the Chicago, 

 Milwaukee and Saint Paul Eailway, near the northwest corner of section 

 35, township 101 north, range 49 west, and in a road cut near the middle 

 of the west line of section 33 in the same township. 



The region south and southwest of Granite, Iowa, also shows a number 

 of sections in which both loesses and sometimes Kansan drift appear. 

 One of these exposures is near the southwest corner of section 19, in which 

 Granite is located. 



The bluish loess is typical post-Kansan loess of fine texture, bluish 

 gray color, with frequent iron tubules, few rounded calcareous nodules, 

 and in this region usually without fossils. 



The yellow loess is looser in texture, coarser as a rule, with very numer- 

 ous small irregular calcareous nodules in the uppermost 2 or 3 feet, and 

 also almost without fossils. 



The loesses are by no means uniformly distributed, for they are entirely 

 lacking on many slopes, and even on the summits of knobs and ridges. 



Conclusions 



The more important conclusions derived from the observations herein 

 briefly recorded are as follows : 



1. The ridges southwest, east, and southeast of Sioux Falls and south 

 of Canton are not a part of the Altamont moraine, but are Kansan. 



2. The plain extending from Shindlar to Canton, South Dakota, is 

 Kansan and not Wisconsin. 



3. The gravel terraces along the Big Sioux are not Wisconsin gravel 

 trains, but are probably Kansan. 



4. The interglacial silt at Sioux Falls is of Aftonian origin, but has 

 been disturbed by the Kansan. 



5. There is no Wisconsin drift in the western part of Lyon County, 

 Iowa. 



