THE LOESS OF IOWA CITY AND VICINITY.* 



BY B. SHIMEK. 



The loess of Iowa City presents no unique features. It 

 is of the type which prevails in the eastern part of the 

 state, being fine and homogeneous; found chiefly on high- 

 lands, especially in its undisturbed condition, and follow- 

 ing their vertical contours, thus varying but little in thick- 

 ness which seldom exceeds twelve or fifteen feet; contain- 

 ing both tubules and loess-kindchen in the usual varying 

 proportions; and more or less fossiliferous. It has been 

 quite fully discussed by McGeet. Lists of the fossils 

 which are found about Iowa City have already been 

 published,! and it is not the purpose of this paper to offer 

 much that is new in this direction, but rather to present a 

 detailed account of the habits of the local modern molluscs, 

 and their bearing on the loess. 



In probably no other locality in the country have these 

 modern and loess faunas been studied side by side more 

 fully than at Iowa City. Besides the early work of Witter, 

 and that of Keyes (chiefly upon State University Museum 

 specimens collected and identified by the writer) , the 

 efforts of Pilsbry and Bayard Elliott were especially note- 

 worthy, though the former published but little, while the 

 latter made no permanent record of his observations, but 

 submitted a part of his collection to the present author, 

 who has been engaged in loess and mollusc studies with 



* This paper was presented in abstract to the Iowa Academy of Sci., 

 December, 1900. 



f U. S. Geol. Sur., vol. xi, pt. i, 1891. 



|WJMcGee,/.c; C. L. Webster, Am. Nat., May, 1887, p. 419; B. 



Shimek, Am. Geol., vol. i, pp. 149-152, 1888; Bull. Lab. Nat. Hist., 



State Univ. la., yol. i, pp. 200-209, 1890; etc. 



