34^ Cretaceous in Minnesota 



was taken for coal were brought to Duluth from that point. 

 During the last Summer (1878) further information has been 

 obtained of lignite along the international boundary line on 

 Nemakon Lake, east of Rainy Lake. 



It thus appears that fragments of the Cretaceous, which 

 cannot bear long transportation, are found throughout nearly 

 the whole State, and that the beds in situ have been discov- 

 ered in a sufficient number of places to enable us to conclude 

 that they extend, or did prior to the spreading of the drift, 

 from the Iowa state line to that of the British Possessions. 

 The only portions of the State where these indications do not 

 exist, are the triangle north of Lake Superior, and the so- 

 called driftless area in the southeastern corner of the ^tate. 

 These are both many hundred feet lower than the central and 

 western portions where the Cretaceous is known to exist, and 

 must have been buried under the Cretaceous ocean unless by 

 some great warping of the crust they were relatively much 

 higher then than now. There is no evidence of such warping; 

 hence it is more likely that unfavorable circumstances have 

 prevented the preservation of the beds or concealed them, so 

 as to delay their discovery. 



A line drawn from the west end of Hunter's Island, on the 

 Canadian boundary line, southward to Minneapolis, and thence 

 southeastwardly through Rochester, to the Iowa state line 

 would, in general, separate that part of the State in which the 

 Cretaceous is not known to exist from that in which it does. 

 It is not here intended to convey the idea that the whole State 

 west of this line, is spread over with the Cretaceous, because 

 there are many places where the drift lies directly on the Sil- 

 urian or earlier rocks ; but throughout this part of the State, 

 the Cretaceous exists at least in patches, and perhaps once ex- 

 isted continuously. 



The beds of this formation that occur in Minnesota, belong 

 to the lower portion. The Dakota Group of Dr. F. V. Hay- 

 den, supposed to be the equivalent of the Nishnabotany sand- 

 stone of Iowa, is probably represented by the white sand- 

 stones at Austin and on the Blue Earth, and by the stone 



