On the Minerals near Lake Superior. 81 



Prehnite, in green stone, from islands in the Pays plat r 

 The place called Pays plat, in Lake Superior, is a very ex- 

 tensive bay, filled with islands. The islands are of green 

 stone, and green stone porphyries, granite, and various gra- 

 nitic aggregates, neither differing essentially in composition, 

 nor in their height, from other parts of the surrounding Coun- 

 try. The Mamelles of Lake Superior are on the Pays plat. 

 The Mamelles are two conical mountains, of such exact and 

 uniform proportions, as to illustrate the propriety of the one 

 name, in the same remarkable manner that they denote the 

 impropriety of the other. I cannot conjecture why this neigh- 

 bourhood has been called a flat country, (and it is so describ- 

 ed upon the maps,) unless it relates to the bottom of the Lake, 

 which is here more flat, and the water more shallow, than in 

 any other place. 



Crystalized red feldspar, and quartz crystals associated, form 

 an extensive bed, at Point aux tourtres, Lake Superior. 



Satin spar, in a green stone cliff, at Portage des Outard, In- 

 dian Territory, west from Lake Superior. 



Jasper and chalcedony, at Height of land portage, beyond 

 Lake Superior. 



Staurotide, in well defined crystals, in mica-slate of Lac a 

 la Croix, and river Malign. N. W. Indian Territory. 



Pitchstone, from the chasm of the mountain, at the Falls 

 of the river Kamanistiguia. N. W. Ter. 



Jasper, flint, and calcareous spar, same place. 



Red jasper with specular iron. River Kamanistiguia. 



Black flint, in beds at the Rapide pares?eux of the river Ka- 

 manistiguia. 



11 



