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



lengthen along the intersection of the lobes toward the north 

 and later toward the northeast. 



As the lobes became more attenuated and separated, the 

 moraines, though still having an acute angle ending in a more 

 or less tapering ridge, would become more divergent toward 

 the south. During the formations of successive moraines, 

 this acute angle would be the scene of copious drainage from 

 the adjacent sides of the two lobes. This drainage would be 

 mostly toward the south. One result of this may be seen in 

 the location of streams, as in the case of the upper portion of 

 Otter Tail River and the Pelican, Buffalo and Wild Rice 

 Rivers. There would also be abundant accumulations of sand 

 and gravel in the form of terraces and plains between the two 

 members of the interlobular moraine. But the matter will be 

 more fully understood after a tracing of the moraines. 



The First, or Altamont, moraine was evidently formed 

 when the ice was near its maximum stage in the Wisconsin 

 epoch and probably when the Lake Superior lobe was con- 

 fluent with the western lobe and its branch occupying the 

 Minnesota valley ; so that the moraine was formed extending 

 as far south as Des Moines and thence northwest, passing a 

 little east of Minneapolis and so on northeast quite directly 

 toward Keweenaw Point. 



During the formation of the Second, or Gary, moraine, the 

 two sheets of ice began to show their separate character and 

 probably began to accumulate to an indefinite extent heavy 

 deposits of drift extending west and northwest from Minne- 

 apolis, possibly uncovered, at least in its later stage, as far west 

 as Wright and Meeker Counties. From the appearance of 

 blue till overlying the red in eastern Minnesota we may infer 

 that some time previous to this stage the western lobe extended 

 farther east. Whether this was before or subsequent to the 

 main accumulations of drift northwest of Minneapolis is unde- 

 termined. 



During the formation of the Third, or Antelope, moraine, 

 while we may suppose the Lake Superior lobe receded but 

 little, or may, possibly, have advanced somewhat from its closer 

 connection with the fountain of ice northeast. The slender lobe 

 occupying the Minnesota valley receded to a point near the 

 southern line of Minnesota upon the south, and on the south- 

 west had withdrawn from the eastern slope of the Coteau des 

 Prairies. Upon the east it seems to have receded into Meeker 

 and Kandiyohi and Pope Counties. The prominent morainic 

 accumulations along that line may have been partly accumu- 

 lated at a previous stage. The valley of the north branch of 

 Crow River lay between the Minnesota and Lake Superior lobe 

 at this time. 



