GEOLOGICAL EXPLORATIONS AND LITERATURE. 



13 



LITERATURE. 



The following is a list of all piiblicatitms which we have met with in 

 any way referring to the PenoketvClogebic district, lieing arranged chron- 

 ologically, the notes and quotations attached to the name of each work will 

 serve to show more fully than has been done in previous pages the history 

 of our subject, up to the time of the special investigations upon which the 

 present volume is particularly based. The dates are the years of publi- 

 cation. 



1849. 



Whitney (J. D.). Letter to Dr. C. T. Jackson, in .Taekson's Rej)ort on the 

 Mineral Lands of Lake Superior, Senate Documents, 1st session, 30tli (Jougiess, vol. 

 II, No. 2, 1847-'48, p. 223-230. 



Whitney's two traverses of the Gogebic iron belt have already been 

 mentioned and indicated on Fig. 1. In this report we lind the tirst men- 

 tion of the results of his oliservations on the two lines followed, as also 



XLVD XLVI XEV XUV ipTiT ^.n 



Fig. 1.— KeproductiDU of liaint's and "Whitney's geological map of region between Agogebic lake and iIonti>;iI river. 



of the observations of Mi'. Banies along a line 12 miles farther to the 

 east. The exact courses of these traverses are given in a volume sul»se- 

 quently referred to, from which also is taken the geology of tlie map of 

 Fig. 1 . From this map it will be seen that no suspicion was raised in 

 Whitney's mind ms to the existence in this region of his "Azoic slates," 

 these slates appearing under this name over a large ))art of the very iiiaji 

 of a portion of which Fig. 1 is a reduced copy. The ti-appean rocks which 

 belong to what we now designate as the Keweenaw or copper-bearing 

 series, are made to lie directly against the "granite and syenite," without 



