BELTRAMI COUNTY, 1899. J. E. TODD 



similar flow of glacial waters. passed from Turtle lake northward to Mud lake and 

 the Mud River valley, reaching lake Agassiz. This history is plainly the commence- 

 ment of that series of events which characterized the region of the upper Mississippi, 

 marked by a fluctuating glacial lake caused by the Lake Superior ice-lobe, one of 

 whose later outlets was by way of the remarkable chain of lakes described in con- 

 nection with Hubbard county (Plate XXXIX). This is a very important and inter- 

 esting part of the glacial history of the state which remains to be worked out by 

 detailed field examination. 



Archean (and perhaps Keweenawan) rocks are found on the islands and shores 

 of Lake of the Woods, and Mr. Todd suggests that probably Cretaceous constitutes 

 the nucleus of Beltrami island. N. H. w. 



