52 THE TEXOKEE lEONBEAEING SERIES. 



Siiiwpais of the SlratUjraphij of the tluroniun of the I'enokec region, IViaronsiii — Conliinued. 



Average 

 thickness. 

 Formaticiii. Feet. 



XI. Covered, but probably micu-sliitc , £80 



XII. Black mica-slate: aphaiiitic; at timo,s iliiastolitic 225 



XIII. {^liloritic (liorite-schist 3.5 



XIV. rUnrk miea-slate, like XII, oitcli chia.sti)litic 375 



XV to XVIII. AlteruatioiLs "f l)lack inica-.slatos, with nuartzites and (|iiart/,srhists.. .. 675 



XIX. (Ireenstoiie-schist; :iplianitio; tile Iioriibleude anil plagioclase much ;iltereil 260 



XX. Covered, but probalil.v like XXI 525 



XXI. iliea-schist; from ajpliaiiitic to medium graiiieil; im-ludiug hands of light gray 

 i|uartz-schist, the mira becoming subordinate; all varietie.s having a back- 

 ground of (juartz: thi' mica wholly biotite; penetrated by veins and nuisses of 

 very coarse, pink to lirick red biotite granite; total on Bad river, 4,960 feet. 

 Seen farther east, higher layers, 2,500 feet ; in all 7, 460 



Total 12,800 



(Pp. 104-105.) 



Tlie numerous local details of this volume are made frequent use of 

 in the following jjages and on the accompanying maps. 



JuLiEN (Alexis A.). Microscopit; Exiimiuatiou of Eleven Rocks from A.sliland 

 County, Wisconsin. In the Geology of Wisconsin, vol. iii, pt. 3, x\.ppendix B, pp. 

 224:-238. With one colored microscopical plate. 



This paper includes detailed descriptions of the following rocks : (1) 

 Chloritic gneiss, from the lower gneisses at Penokee gap ; (2) crystalline 

 limestone ; (3) tremolitic magnetite-slate ; (4) black feldspathic slate ; (5) 

 chloritic diorite ; ((i) inagnetitic mica-slate ; (7) chiastolitic mica-slate ; 

 (8) diorite greenstone-schist ; (9) inagnetitic mica-schist — all from the Bad 

 river section through the Iron-bearing slates; and (10 and 11) two chryso- 

 litic diabases from tlie overlying copper series. 



Wright (C. E.). The Huronian Scries West of Penokee Gap. In the Geology 

 of Wisconsin, vol. iii, pt. 1, pp. 239-301. With one atlas plate and ten volume plates. 



This report, the result of a special exploration with reference to the 

 occurrence of iron ores in the slaty series west of Bad river, embraces 

 three chapters, which are entitled, respectively, " Dij)ping Needle and Solar 

 Dial Compass, and the Method of Employing Them," " Geological Cross Sec- 

 tion of Penokee Iron Range," nnd "Special Examination of Penokee Iron 

 Range West of the Gap." The first of these chapters calls for no consid- 

 eration from us. The third chapter is occupied with local details, arranged 



