38 



THE PENOKEE lEOX-BEARING SERIES. 



placed at the top of the series is really as we have already insisted, but 

 part of the great development of gabbro which lies at the base of the 

 Copper-be.aring series. The facts given in this tabulation for the Black 

 and Bad river sections are based on the observations made by Brooks on 

 his rapid trip through the region in 1871, above refeiTed to. In a later 

 publication he accepted the Bad river section given ]>y R. D. Irving.^ 

 The following is the portion of Brooks's tabulation referred to- 



Black river series. 



Compact greenstone, with green chertyC?) layers. 

 Bright red specks of jasper and crystals of 

 pyrite. 



Greenstone : holds grains of glassy (juartz and 

 appears chloritic. 



Hematitic iind miKjiivtic quartzi'se flaij (like Mar- 

 quette Hag ores). 



Gray, green, anil hrown handed ferrmjinous, silice- 

 ous slate, witli strong rhonihohedral cleavage. 



Grayish .and greenish handed schist, weathering 

 brown, apiKircntly <A7())itic, wMijaspery layers 

 Contains pyrites. lu places apparently felsitic 

 and again a]ilianiti<'. 



[Covered.] 



Ferruginous, handed (pnri)le and green) cherty 



sdiist (magnetic). 

 Banded ferrnginons jasper schist. 

 Ferrugiuons, siliceous Jtuys (not m.aguetic). 

 Arenaceous quurtzose schist. 

 Reddish quartzitc. 



Hydrous magnesian or argillaceous schist. 

 Greenstone. 



Banded cherty schist and schistose cherty breccia, 



more or less ferruginous. 84, 85. 

 Compact, liard greenstone. 

 Very soft, ajiparently cliloritic greenstone. 

 Gray, banded, slaty schi.tt. 



[Covered 100 steps.] 



Greenstone. 



Banded ferruginous, siliceous schist, strongly mag- 

 netic. 

 Greenstone. 

 Banded ferruginous slate. 



Massive greenstone, apparently chloritic. 

 Banded ferruginous ^'aspo' schist. 



Bad river aeries. 



Red, gray, coarse and fine grained granitic rock, 

 rarely schistose. 



Greenstone or liornhlende rock, apparently chlo- 

 ritic (.somcwlial sott, l)Ut tough). 

 [Covered about J mile.] 



Clav slate? 



Magnetic <imphiholic quartzose flags and quartzose 

 magnetic ore. 148. Heavy bed forming crest 

 of ridge. 



Black clay slate without oldique cleavage. 



Gray quartz achist, liauded with occasional lam- 

 ina' of magnetic ore. 



Grayish and reddish quartzose schist. 

 Greenstone (thin bed). 



Soft, light, gray-greeu slate, probably chloro- 

 argillaceous. 



Gray quartzose schist, faintly banded. 



Gr.ay to wliite, massive quartzite. (Thin bed.) 

 Calcareous rockf 



Amphibole schist and perhaps hornblendic gneiss 

 in heavy beds. 



[Covered. J 



' Geol. of Wis., 1880, vol. in, table opp. p. 450. 



