on THE TENOKEE IKON-I5EAEING SERIES. 



slight, though it appears to bu moic considerable elsewhere.' This interval was 

 probably entirely occupied by the disturbance and uietain()ri)liisni of the Huroniau 

 strata- above described. Indeed, there is rt^ason to think that this was only partially 

 accomplished wlien tlic Keweenawau eruptions began. Sedimentary deposits must, 

 however, have been in progress while the slow upheaval was taliiug place. If we 

 could reach these dei)osits we should doubtless find them in no very esseutial respect 

 different from those which preceded and followed. Prof. Selwyn, director of the 

 Canadian Geological Survey, as the result of liis studies upon tlie equivalent forma- 

 tion at the east, does not recognize any interval between tlie two series, audit may 

 be that what is but a moderate break in Wisconsin is bridge<l by what seems to be 

 an essentially continuous series in the eastern region. (Pp. 1(4-1)5.) 



Irving (R. D.). Lithology of Wisconsin, Geology of Wisconsin, vol. i, pt. li, 

 chapter iii, pp. o40-361. 



A general account of the various rock species of Wisconsin known to 

 date (May, 1882). So far as the Penokee district is concerned the newer 

 material here included is the same as that given in the volume next referred 

 to. 



Irving (R. D.). The Copper Bearing Rocks of Lake Superior, Monograph U. S. 

 Geol. Survey, vol. v, 1883, 20 plates and maps. 



This volume is of course chiefly devoted to the Keweenawau or Copper- 

 Bearing Series, but incident to a discussion of the relation of these rocks 

 to the older formation is given a brief summary of the results obtained in the 

 Penokee district by the Wisconsin Survey (pp. 391-3il2). There is also given 

 a map (PI. xxii, Monograph v) of the region extending from lake Gogebic, in 

 Michigan, to Numakagon lake in Wisconsin, and northward to the shores of 

 lake Superior, on which the entire lengtli of the Penokee-Gogebic belt is 

 shown, the Michigan end of the belt having been platted from the notes 

 on the U. S. Land Office plats and from statements in the j)apers of Pumjielly 

 and Brooks, above referred to. The 1)ek is also shown in its entire extent 

 on tlie general maps (Plates i and xxviii, Monograph v) which cover the 

 entire lake Superior region. Other points discussed having bearing t)n our 

 present subject are the relations of the Penokee series to the Animikie series 

 of the north shore of lake Superior (pp. 386, 392), the general relations of 



' Fullci' (Lata than arc given in th(^ Wisconsin reports, rclatinf; to tlic nnconforniity of tlui Hiironian 

 and Kowuenawan series, may be fonnd in the forthuomins Monograph of Prof Irving, on tlie Kewee- 

 nawan or Copper-Bearing Series, issned nuder the anspiees of the U. S. Geol. Survey. See also the 

 earlier paper of Major Brooks, Am. .Jonr. Sei.,3d series, vol. xi, 1875. 



