THE 



JOURNAL OF GEOLOGY 



OCTOBER-NOVEMBER, igu 



THE IOWAN DRIFT 



SAMUEL CALVIN 



CONTENTS 

 Introduction 



Is there an Iowan Drift ? 

 Has the Term Iowan Been Correctly Applied ? 

 Cause of Confusion in Use of the Terms Kansan and Iowan 

 Effect on Texts and Maps of Making Certain Proposed Changes in 



Use of the Terms 

 Evidence Concerning the Iowan Drift and Its Geological Relations 

 i. The Iowan Drift IS 



2. The Iowan Drift is Young as Compared with the Kansan 



3. The Iowan Drift is not a Phase of the Kansan 



4. The Iowan Drift has very Intimate Relations to Certain Bodies of 



Loess 



5. The Iowan Drift is not Related to the Illinoian 



INTRODUCTION 



Is there an Iowan drift ? Whatever the reader may think 

 about it, the question seems to be in order. Three papers have 

 recently appeared in which the Iowan drift receives more or less 

 attention. 1 Two of the papers go so far as to question the very 

 existence of such a sheet of drift as that which geologists have for 



'Frank Leverett, "Weathering and Erosion as Time Measures," American 

 Journal of Science, XXVII, May, 1909. 



, "Comparison of North American and European Glacial Deposits," 



Zeitschrift fur Gletscherkunde, IV, Berlin, 1910. 



T. C. Chamberlin, "'Comparison of North American and European Glacial 

 Deposits,' by Frank Leverett;" a review of the second paper, Journal of Geology, 

 XVIII, No. 5, July-August, 1910. 

 Vol. XIX, No. 7 577 



