The '^ A II {/ en'' -Gneiss Ared. — Lnqiier and I?ies. 249 
accompanied by bleaching and the separation of magnetite, 
which forms abundant included grains irregularly distributed. 
Biotite is rarely present, although somewhat abundant in 
No. 14g, where it showed intergrowths with hornblende and 
also a few inclusions of the latter mineral, proving tliat 
the hornblende began to form first but had not ceased before 
the commencement of the biotite crystallization. 
IlnfiJe is common in the form of slender needles in the feld- 
spar. 
Apatite, of the usual habit, occurs as inclusions in the feld- 
spar, and a few prismatic crystals of tonrmaliiie were also 
found. 
3ffii/neiife is sparingly present, usually as inclusions in the 
hornblende. 
Pyroxene, in small granular masses, was seen in one sec- 
tion (14g). 
, Titanite, zircon and pijrite are rare, as is also interstitial 
qixurtz. 
Dike at 27. This intrusive varies considerably in texture 
from coarse to fine and also in mineralogical composition. 
The sections, from the more central portions of the outcrop, 
show that the dike consists essentially of a hornblendic rock 
(amphibolite) composed of an aggregate of interlaced horn- 
blende and biotite individuals, both containing plentiful in- 
clusions of magnetite. Towards the edges of the dike the 
rock appears as a mixture of irregular plates and l>roken frag- 
ments of hornblende, intimately mixed with granular pyroxene 
and titanite with subordinate biotite. The hornblende, in tliis 
phase, contains inclusions of titanite and granular pyroxene, 
which latter show no connection, in their optical orienta- 
tion, either with respect to themselves or their host. Augite 
has also been noticed by J. F. Kemp, both as inclusions in. 
and at the same time surrounding, hornblende crj'stals. evi- 
dently formed from the latter mineral by resorption.* 
Hornblende occurs as the prevailing mineral in lath-shajx-d 
individuals, broken fragments or shreds. The color is green 
and the mineral exhibits its characteristic absorption and small 
extinction angle. No evidences of uralitization are seen, ami 
the before mentioned inclusions are common. 
*Amer. Jour. Sci. (3), xxxvi, 251, 1888. 
