304 THE MARQUETTE IRON-BEAltING DISTRICT. 



prove to be from a clastic rock. There are, however, jjebbles of finely 

 crystalline cherty or jaspery quartz. The background of the conglomerate 

 is slate or graywacke, which does not differ in its character from the slates 

 and graywackes of the Wewe formation (described on pp. 265-269), except 

 that a large amount of chlorite has developed, and in some cases hornl)lende. 

 The quartzites comprise all of the phases described in the general descrip- 

 tion (pp. 290-291), but the less mashed and nonljrecciated phases are more 

 common, so that in most cases the fragmental character of the rocks is 

 evident at a glance. The purer quartzites are either cemented by enlarge- 

 ment or bv enlargement combined with interstitial independent quartz. 

 These purer phases vaiy into ferruginous, sericitic, and chloritic quartzites, 

 and these, by an increase of the sericite and chlorite, and a decrease in the 

 size of the (piartz grains, into novaculites or graywackes. In some places 

 a small amount of interstitial hornl^lende develo})ed. In places the ledges 

 are cut by quartz veins composed of intimately intermingled and interlock- 

 ing, finely and coarsely crystalline quartz. The slate and graywacke 

 phases are largely sericite-slates, identical with those of the Wewe forma- 

 tion. Like them, they are in places brecciated, and veined by secondary 

 cpiartz ]ningled in places with oxide of iron. In the backgromid with the 

 chlorit(^ there is, in some specimens, a small amount of hornblende. 



Area east of Teal Lake. — Tlie Uirgest aud uiost coutinuous exposures of the 

 formation begin north of the east end of Teal Lake and extend to the Carp 

 River, a distance of about 3 miles (Atlas Sheet XXX). The precipitous 

 bluffs making up this area are known as the ]\Iakwa Hills. For the central 

 pai't of the area the exposures are practically continuous from the bottom 

 of the formation to the top. In many particulars tliis (piartzite is similar 

 to that west of Teal Lake, but it difters from that in being much thicker 

 and in containing many interstratified argillaceous beds. In fact, a large 

 portion of the exposures are slate and graywacke rather than quartzite. 

 As has been explained in the previoi;s sections, it is probable that the 

 lower horizons are really the time equivalent of the Wewe slate, the Kona 

 dolomite, and the Mesnard cpiartzite. In the atlas sheet the ridge is appor- 

 tioned between these four formations, each later formation overlapping the 



