ON THE MINNESOTA RIVER. 



483 



two hundred and thirty feet above the river, and is composed of coarser materials. 

 The view from these heights is exceedingly fine, and the disposition of prairie and 

 groves of timber almost conveys the idea of a cultivated country. 



The commencement of what is designated the " Bois Franc* District," sets in 

 above this, and extends for the distance of about forty miles along the course of 

 the stream, and is probably the best agricultural region on the St. Peter's. 



Some singular rounded drift-hills were observed in this vicinity, supporting a 

 heavy growth of tall grass, with a few isolated trees on their summits. Some of 

 these are so regular in their outline, that they might almost be mistaken for 

 ancient earth-works, such as are common on the Upper Mississippi further south. 



About five miles beyond the mouth of Witakantu River, a small stream coming 

 in from the northwest, and a little below Abort's Run, we found, on the right bank 

 of the river, the " fawn-coloured limestone" mentioned by Featherstonhaugh. The 

 rocks at this place are exposed to the height of eighteen feet above the water-level. 

 In the ascending order there is, first, ten feet of rather thick-bedded salmon-coloured 

 magnesian limestone, somewhat cellular, the cells being coated with carbonate of 

 lime ; then succeeds two feet of magnesian limestone, in layers varying from a half 

 inch to two inches in thickness, succeeded by six feet of intercalations of sandstone 

 and magnesian limestone, on which rests the drift, which has a thickness of over 

 one hundred feet. 



We could not discover any organic remains in the strata at this place, but in 

 lithological aspect they so closely resemble the beds of passage between the Lower 

 Sandstone and Lower Magnesian Limestone on the St. Croix and Upper Mississippi 

 Rivers, that even in the absence of fossil data, little doubt could be entertained 

 as to their geological position. 



Above this place the river has a very tortuous course, and the hills increase some- 

 what in elevation. At the mouth of a small stream, which the voyageurs called 

 Reef Creek, the altitude of the table land is two hundred and eighty feet above the 

 river ; on the surface are numerous erratics, from a few inches to several feet in 

 diameter. They consisted chiefly of granite, gneiss, porphyritic and greenstone 

 trap. 



Above Bois Franc Creek, the hills near the river have an elevation of about one 

 hundred feet, with a very gradual slope towards the margin of the water ; but at 

 the distance of a mile and a half back, we observed other ranges running parallel 

 with the river, which seemed to be from eighty to one hundred feet high. 



At " White Rock Bluff," situated on the right bank of the river, about six miles 

 below Traverse des Sioux, is an interesting exposure of the Lower Magnesian Lime- 

 stone and Lower Sandstone. The height of the bluff is seventy-two feet above the 

 water-level. The succession of the beds here in the ascending order is as follows : 



Feet. 



1. Talus, covered with fragments of sandstone and magnesian limestone, 30 to 40 



2. White and brown sandstone, composed of rounded, rather coarse, 



semi-transparent grains of quartz, loosely cemented, . . 20 



3. Green siliceous earth, ...... 1 



* The Bois Franc is a term used by the Canadian French to designate the deciduous from the ever- 

 green trees. 



