J. K Todd — Revision of the Moraines of Minnesota. 477 



the south side of the divide along Lake Superior. To this 

 stage we refer the morainic ridge separating the two portions 

 of Red Lake, the prominent points of the so-called Beltrami 

 Island south of the Lake of the Woods, the outer portion of 

 the Mesabi range. The course of the moraine around the Lake 

 Superior lobe we do not venture to point out, except to suggest 

 that it may include the moraine south of Lake Pokegama and 

 probably some portions in western Aitkin and Mille Lacs 

 Counties, together with some portions of the singularly elon- 

 gated ridges trending northeast, portions of which we have 

 referred to the preceding stage. Our conception is that at this 

 time the Superior lobe had become more attenuated and was 

 traversed by channels draining southwest which first tended to 

 form osars ; and these eventually grew into interlobular 

 moraines somewhat as McGee has found in eastern Iowa. 



During the formation of the Ninth, or Vermillion, moraine 

 the ice lobes had retreated some distance from each other, and 

 the northern was forming the Vermillion moraine as has been 

 traced by Mr, Upham, while the Lake Superior lobe was form* 

 ing the moraine south of CJoqnet River ; and probably the 

 northeastern portion of the northeast ridge in Carlton County 

 may have been formed at this time. 



In this way we venture to attempt a solution of the unusually 

 perplexing problem of the morainic accumulations of the 

 northwest. The first stage of Lake Superior, when its highest 

 beach was formed and its outlet was by the Bois Brule into the 

 St. Croix River, followed soon after the vacation of this ninth 

 moraine. 



Before closing, we may add a few suggestions as to the pos- 

 sible correspondence of the Minnesota moraines on the south 

 side of Lake Agassiz with those traced by Mr. Upham and 

 published upon his map in his work upon Lake Agassiz. We 

 have little difficulty in correlating the first three moraines as 

 has been done in the third annual report of the U. S. Geolog- 

 ical Survey. The fourth seems to correspond with the fourth 

 as published in Bulletin 11-i, U. S. Geological Survey. This 

 may have had upon its western member a double development 

 because of the more rapid retreat of the ice from that direc- 

 tion, which would explain the scattered development of the 

 moraine along the Cheyenne River in North Dakota. The 

 fifth seems to correspond in position with one indicated by Mr. 

 Upham as following up the east side of the Cheyenne River and 

 more distinctly developed south of Devil's Lake. The sixth 

 probably corresponds to the Tiger Hills or the Arrow Hills 

 moraine, and the'seventh to the moraine crossing the Manitoba 

 and Northwestern R.R. near Mennidosa on the Little Saskatch- 

 ewan ; while the eighth and ninth moraines extend into regions 

 unknown west of Hudson Bay. 



