42 THE GEOLOGY OP MTSrSTESOTA. 



[Keating, 1813. 



In the Red River valley Keating mentions numerous salt springs, one 

 being situated at the confluence of Red Lake river with the Red river of the 

 North; states that although the soil of the prairies is occasionally sandy, 

 it is generally argillaceous and rather dry, yielding along the river valley 

 and its tributaries a good grass, though at a distance a rather scanty growth, 

 but being extremely fertile wherever trees were seen to be growing ; and 

 attributes to the annual fires that run over the prairies the principal agency 

 in keeping the country treeless. 



ON THE NORTHERN BOUNDARY. 



Respecting the northern boundary of Minnesota, Prof. Keating gives 

 the first geological information, besides naming for the first time several of 

 the principal rivers in that part of the state. Ascending the Winnipeg river 

 from lake Winnipeg he found a great contrast between the adjacent country 

 and that through which he had been traveling hitherto. The country is 

 rocky very soon after leaving lake Winnipeg, with the crystalline rocks 

 common to the northern part of Minnesota, there being between lake 

 Winnipeg and the lake of the Woods several alternations from red granite 

 and gneiss to slate and schists. The timber which sets in with this change 

 in the character of the rocks, consists of a great abundance of evergreens, 

 deciduous trees being rather the exception. The conifers were found to 

 be tamarack, juniper, spruce, white pine, pitch pine &c., interspersed with 

 spots where aspen and birch were found common, and other spots of hazel, 

 willow and cherry. The rocks and the general characters of the country at 

 the lake of the Woods were stated to be similar to those of the Winnipeg 

 river. The lake is filled with islands, all resting on the solid rock which 

 was found to be generally a greenish or micaceous slate. One island, known 

 as Red Rock island,* was of a reddish granite. The direction of the "strata" 

 of the mica slate was stated to vary from N. 60 to N. 80 E. and the angle 

 of inclination to vary from 65 or 70 to perpendicular; but it is quite prob- 

 able that Keating here refers to the direction and dip of the slaty cleavage. 

 Although no limestone in situ is reported by Keating, he refers to the fact 

 that Dr. Bigsby, whom he met on the British Northern Boundary Com- 



Subsequently named Keating Island by Mr. G. M. Dawson. 



