GEOLOGICAL EXPLORATIONS AXD LITERATURE. 17 



The jjranitc ol' tlic wIkiIc (if this iiortioii of tht' dislrict is very coarse grained aud 

 crystalline and is <liaraileri/ed hy a iiredouiinauce of fehlsjiar aud an almost entire 

 absence of mica. (I'p. 47, iS.) 



The stateiiiuuts in the ;il)(>V(j (quotations rest, of course, upon the few 

 oKservatious hy Messrs. Wliitney aud Barnes. It is manifest that no 

 thought of the existence of iron-l)earino' slates between hike Cxogebic and 

 the Montreal river was entertained. Tliis is the more singular since the 

 discoveries of ii-on-l)earing slates l)y .Mr. Wliittle.sey west of the ^Montreal 

 river (subsequently noted) were known to Messrs. Foster and Whitney, as 

 ai)pears from their statement (page 51). 



1853. 



Whittlesey (Charles). Geological Report on that portion of Wisconsin bor- 

 dering ou the south shore of Lake Superior, surveyed in the year 1840, under the direc- 

 tion of David Dale Owen, U. S. Geologist, by Charles Wliittlesey, head of subcorps. 

 In Report of a (reological Survey of Wisconsin, Iowa, aud Minnesota, by David Dale 

 Owen, IT. S. Geologist, Philadelphia, 1852. 



It seems that Dr. Owen himself must have crossed the westernmost 

 end of the district with which we are concerned near Numakagron lake. 

 This appears to have been in 1848 or 1849, but no observations of impor- 

 tance were made (pp. 169-160). Dr. Randall, one of Owen's assistants, 

 appears to have made the first discovery of iron-bearing slates in this 

 district while foHowing the Fourth Principal meridian in 1848 (p. 444). 



Col. Whittlesey's own exploration was made in 1S49, in whicli year he 

 followed the belt of iron-bearing slates from the vicinity of iMontreal river 

 to English lake. The following quotation will serve to show wluit wi^-e his 

 views as to the general structure of the whole Ba<l river coimtry in Wis- 

 consin : 



The accompanying map and sections are intended to represent at one glance the 

 principal features in the geology of this region. The extent, elevation^ and relative 

 thickness of the various formations, as well of solid rock as the looser earthy de])osits, 

 will there appear in a more compact and intelligible form tlian I could give them by 

 written descri]itions, liowever elaborate. 



There afe four formations or great classes of rocks sliownoii each section. These 

 all appear in the same order of succession, reckoning from the lake southerly, aud may 

 be grouped thus : 



MON XIX -• 



