A SKETCH OF GEOLOGICAL INVESTIGATIONS IN 

 MINNESOTA. 



Prior to the beginning of geological investigations in Minne- 

 sota there was a period of exploration and travel, in the pub- 

 lished accounts of which are some references to the strictly 

 geological features of the state, 1 and others from which some 

 inferences can be drawn bearing upon the natural features and 

 often upon the geology. Omitting the references made by 

 Champlain in 1615 to the "Grand Lac" and the explorations 

 made by Grosselliers and Radisson between Hudson's Bay and 

 Lake Superior in 1659, and the maps of Franquelin dated 1688, 

 and Beauharnois, dated 1737, it is sufficient here to mention 

 only the discover)' of the Falls of St. Anthony by Father Hen- 

 nepin who accompanied Accaultin an expedition up the Missis- 

 sippi, sent out by La Salle, in 1680. Hennepin's original 

 account of the falls has been used as a datum from which to 

 calculate the amount of recession from their discovery to 1857. 

 This important geological phenomenon was viewed through the 

 eyes of a religious enthusiast, and he named them in honor of 

 St. Anthony of Padua, his adopted patron saint. Sieur Du 

 Luth about the same time was making some additions to the 

 known geography of the state. In 1683 Le Sueur made the 

 earliest examination of the valley of the Minnesota. He men- 

 tioned a " green earth," which he supposed to be carbonate of 

 copper, at a point near Mankato, and a large mass of native 

 copper on Lake St. Croix. Jonathan Carver traveled exten- 

 sively in Minnesota in 1766. He gave a full description and an 

 illustration of the Falls of St. Anthony, which have served to 



1 There is a " sketch of explorations and surveys in Minnesota " in Vol. I. of the 

 final report of the present " Geological and Natural History Survey " of the state. 

 This deals largely with the early explorations. In Bulletin No. I, of the same survey, 

 will be found some account of the institution and progress of the present survey. 



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