PETROGRAPHICAL CHARACTERS OP UPPER HURONIAN. 167 



way cany (portage). The rocks at this point are an alternating succession 

 of mica-schists, some of which are very quartzitic, and hornblende-gneisses 

 (altered igneous rocks) in thick beds. In these the bedding and schistosity 

 agree, or else differ so slightly as not to be noticeable. These rocks out- 

 crop in bold knobs for some distance away from and on both sides of the 

 Michigamme River at the carry and also form the steep cliffs between which 

 the river flows. In some places they are more or less ferruginous, and 

 at one point near the head of the rapids exjjloring for iron has been done. 



These crystalline schists are separated from the undoubted sedimen- 

 taries at the north by an interval of about one-half mile, and are separated 

 to the south by a smaller interval from the next rocks, which are also of 

 sedimentary origin, though of highly metamorphosed character. These 

 latter consist of micaceous graywackes which grade over by increasing 

 metamorphism into rocks which are indistinguishable from mica-schists and 

 mica-gneisses. There can be no doubt as to the clastic character of these 

 rocks, as one may see on the outcrops of the least altered phases the normal 

 as Avell as the false bedding. The bedding of these micaceous graywackes 

 agrees with that of the mica-schists at the Norway can-}-, and in them the 

 schistosity is usually nearly parallel to the bedding, though at times cutting 

 it at varying angles. These rocks vary in grain from fine to very coarse. 

 They are most all a light-gray color. In two cases the presence of large 

 porphyritic crystals of staurolite was observed. Garnet was found in but 

 a single specimen, and no andalusite was seen. The scarcity or absence of 

 such minerals is made noticeable by the fact that they are so abundant in 

 the adjoining Marquette district. The contrast is the more marked since the 

 Crystal Falls rocks are cut by and included in granite, and in the Mar- 

 quette district these intrusives are absent. Splendid sections through the 

 metamorphosed sediments are offered by the river sections in sees. 14, 24, 

 35, and 36, T. 42 N., R. 32 W., on Paint River, and at Peevie^ Falls, sec. 

 32, T. 42 N., R. 31 W., on the Michigamme River. 



It should be noted that thus far no griinerite-schists which owe their 

 origin to the metamorphism of ferruginous sediments have been observed 

 in the Crystal Falls district; nor does the brilliant red jasper — jaspilite — 

 which accompanies certain of the ores in the Marquette district, occur 

 associated in large quantity with them in the Crystal Falls district. 



' This name has been given by the lumbermen to the fsills as they lose so many peevies here in 

 breaking jams. 



