J. E. Todd — Revision of the Moraines of Minnesota. 469 



Akt. XLYIII. — A Revision of the Moraines of Minnesota / 

 by J. E. Todd. 



For our knowledge of glacial deposits of Minnesota, so far 

 as has been published, we are indebted almost entirely to the 

 excellent work of Mr. Warren Upharn. Even where others 

 have been employed in detailed work, he has correlated and 

 interpreted the data. The following criticism of his conclu- 

 sions is done with the most friendly feelings and prompted 

 only by the love of truth. It has seemed advisable that the 

 present view should be presented, that the scientific world 

 might judge for themselves regarding the comparative cor- 

 rectness of the two views. 



When called to share in the work of unraveling the Pleisto- 

 cene geology of Minnesota four years since, the impressions of 

 the writer were mainly in harmony with those of Mr. Upham. 

 It has been his province to examine the northwestern counties 

 of the State, and it should be remembered that the interpreta- 

 tion offered below is based mainly upon observations in the 

 western half of the State. The work in Hubbard and Bel- 

 trami Counties soon presented the case in a different light. 

 From a comparison of our map (p. 471, scale, TO miles to the 

 inch) with those referred to below, the salient differences of 

 interpretation will appear clearly. 



It will be seen that, according to Mr. Upham's view, all of 

 the moraines crossing Minnesota and Dakota have been formed 

 by an ice sheet moving southward. Time not permitting us to 

 follow the growth of his views, we take their ripe expression 

 as given in the 22d annual report of the Minnesota Geological 

 Survey. This southerly motion persists without much refer- 

 ence to topography. The stages marked by the separate 

 moraine as recognized by Mr. Upharn are as follows :* 



1. The Altamont, extending into Southern Dakota and to 

 Des Moines, la. 



2. Gary Moraine, extending to Mineral Ridge, near Boone, 

 Iowa. 



3. Antelope Moraine, extending to Pilot Mound in Hancock 

 County, la. 



4. Kiester Moraine, extending into Freeborn and Faribault 

 Counties. 



5. Elysian Moraine, extending into southern LeSeur County. 

 6 Waconia Moraine, extending to Waconia, Carver County, 



Minn. 



* Ice Age in North America, pp. 545-. The Glacial Lake Agassiz, Mod. xxv, 

 U. S. G. S., pp. 14 1-. 



