THE QUARTZ-SLATE MEMBER. 



177 



R. 2 W., Wisconsin; iind again in tlu- NK. \ of the SE. \ Sec. 1, T. 44 \., 

 R. 2 W., Wisconsin, where are to he noted among the more iisnal plia.sesof 

 tlie shite a niunl)er of hxyers of a, pink to hrick re(| and h'ad gi'av sliaU^, a 

 phase which has thus far not heen noted to tlie wi^st of this |)oiiit, llioiigh 

 occurring sonnnvhat lVe([UentIy farther- to th(Muist. 'I'h(^ gi'eater part of the 

 thickness of the Qiuirtz-slate i'oruiatiou is e\pos(>d again at tin; gorge of 

 TyU^rs fork, SE. • of the NE. ^ Sec. 33, T. to N., \l. 1 W, Wisc.nsin, tlie 

 contact with the ovei'lying iron foi-uiation heing tinel\- exposed on the west 

 hank lA' the rivei", as indicatcfd on the following sketch ina[) (Eig. <^). The 









nrrTi 



Dril 



, /" V ,, , ,^ 



Irtm-bearinfj member. Qtrartz-nlate member. 



Fig. «.— Map and Hcctioii Mlnnviii;: jinHitinii nf i-ock cxpuaiircB at 'l\vl"'''« I'ork. (Kruni I'laii- \iv, vul. Ill, Wiai^onain 



(ieuhttiU'ii\ Survey I Sculp: 1 in. — .'JIO feet. 



uppermost vitreous (piartzite shows here ver\- jilainly, while the liody of 



the formation is ilistinctl\' nearer in character to tlie feldspathic ipiartz- 



slate phase al»ove described, altlumgh tlien; are interleaved with the pre- 

 MON XIX lU 



