238 R. D. Irving—Divisibility of the Archean. 
In the southern part of the area mapped, we find ourselves 
in the northernmost portion of a great area of gneiss and granite, 
associated with which in large proportion are highly foliated 
and crystalline hornblendic and chloritic schists, with some. 
mica-schists. In some of these schists distinct evidences*are 
here and there met with of their fragmental origin. These 
rocks which go to make it up, but is seen to be made here of 
assing now beyond this vorthern limit of the gneiss-granite 
tra 
erable alteration. The quartzites are always merely indurated 
sandstones, and often the induration is feeble, and the rock 
little more than a friable sandstone. Except when we reach 
the immediate vicinity of Lake Gogebic, where a change 12 
structure comes about which we cannot now discuss, the layet 
of this sandstone belt dip always to the northward, usually 
at rather high angles. i i 
secting masses, plainly of eruptive origin, occur, but, w! 
exception of these, and of certain belts believed to be 1 P®'. 
of direct chemical origin, the whole succession is made UP “ 
layers which contain but little original crystalline material _ 
to which the term “ metamorphic,” in the sense of more OF © 
ndition, 38 
hardly applicable. oe 
thorough recrystallization from the sedimentary co 
