SO-CALLED PORPHYVRITIC GNEISS OF NEW HAMPSHIRE 721 
display of inclusions, varying in size from small fragments to 
masses twenty feet square, all of which have evidently been 
derived from the older schists to which they are mineralogically 
and structurally similar. These horses are highly ferruginous, 
and weather with the same rusty appearance that characterizes 
the parent rock. So great is their number in some places that 
considerable stretches are veritable flow breccias. But it is 
rather the remarkable crumpling and other evidences of intense 
folding which attract one’s attention to these outcrops. The 
sliverlike horses are very often bent into sigmoid flexures; 
sometimes one is seen to be completely doubled back on itself 
in a nearly closed fold. They are usually much jointed, and 
here and there actual movement along a fault plane may throw 
one part of the inclusion a foot or more out of its normal con- 
tinuity. While there is not much difference mineralogically 
between these inclusions and the rock of the ferruginous terrane, 
yet there is some evidence of a metamorphic change due to the 
granitite. About one of them, some two feet long and a foot 
and a half broad, in particular, a two-inch zone filled with large 
biotites was developed. The biotite of the granitite itself is 
often segregated in large individuals. Many of the horses have 
been considerably melted up, and it is probably the absorption 
in this way of so much of the iron oxides that conditions the 
characteristic deep reddish brown color of the weathered granitite. 
This terrane has but few affinities with the simple Lake 
Winnipiseogee mica-gneisses, where they occur in their normal 
fresh uncrushed habit. No evidence is yet forthcoming that the 
latter are eruptive. Not only do these multitudinous horses 
prove the eruptive origin for the granitite, but its actual contact 
with the ferruginous schists was found on Riley Mountain, and it 
tells the same story. The usual field criteria of the presence of 
horses, apophyses, and intrusive sheets are there exhibited. A 
rock zone of the foregoing description, averaging rather more 
than a quarter of a mile in width, runs southward five miles to 
the Antrim ridge above mentioned, always appearing between 
the porphyritic granite and the main body of schists. 
