16 TEE PESOKEE IRON-BEARING SERIES. 



1851. 



Foster (J. W.) and Wiiitnk\'" (J. D.). Report ou the Geology of the Lake 

 Superior Land J)istrict, Part '2, The Iron Rej^ion, together with the General Geology, 

 Senate Docs., special session, 32nd Gong., Washington, 1851, vol. in, No. 4, 106 pp., 

 with maps. 



This is Foster and Whitney's final i-eport on the iron regions of the 

 upper peninsula of Mieliigan. In it several brief references are made to 

 the region west of Grogebio and south of the trappean beds of the Copper 

 range. We quote as follows (p. 39): 



Farther west another granite belt starts from the hea-d waters of the Ontonagon 

 river, and thence extends to the western limits of the district, intersecting the head 

 of Agogebic lake and crossing the Montreal river about 15 miles from its mouth. 

 Southward it forms the watershed between the rivers of lake Superior anil the Mis- 

 sissippi and passes beyond the limits of this district into Wisconsin. It is probable 

 that this belt is a contiiuiation of that tirst described, but we have not been able to 

 trace the continuity. There is an interval of 20 miles where the surface of the 

 country becomes nearly horizontal and is strewn with accumulations of clay and 

 gravel, burying up the subjacent rocks. 



In the extreme western portion of the district, west of rang'e 40, granite is the 

 predominating rock below the southern boundary of township 47 and is associated 

 with a hornblende rock which sometimes assumes a slaty structure. The granite is 

 mostly a binary compound of feldspar and quartz, the former largely predominating 

 and giving a reddish tinge to the whole rock; mica is present only in very small 

 quantity, while liornblende and chlorite are occasionally scattered in minute particles 

 through it. Nearly the whole of the granitic region in this part of the district pre- 

 sents the most forbidding and d(^solate aspect. Though it forms the most elevated 

 l)ortion of the country, being the watershed between lake Superior and the Missis- 

 sippi, it is low and swampy and filled with numerous lakes, of which over fifty were 

 (grossed by Mr. Burt in surveying the boundary line between Lac Vieux Desert and 

 the Montreal river. There are occasional elevations, which are dry and wooded with 

 sugar maple and which undoubtedly are covered with a good soil, but the larger por- 

 tion of the region presents almost interminable cedar swamps, in the midst of which 

 the granite and lioi-nblende ridges rise, with precipitous walls, rarely to more than 50 

 feet in height above the surrounding country. These ridges are generally very na.r 

 row, and their sides are covered with a thick coating of moss and lichens. Nothing 

 can exceed the desolate solitude of this region. Not even the Indian traverses it; it 

 is destitute of game and its stillness is never broken except by the cravshing of the 

 tornado through the dense forest, tearing up the trees and piling them together so 

 as to present an almost impassible barrier, as if still further to repel the intrusion of 

 man into a region so little fitted for his reception. 



