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NEW YORK STATE MUSEUM 



of this vicinity is chiefly banded amphibolite, sometimes very mas- 

 sive and basic, at other times abundantly injected with granitic 

 material which has cut it up into narrow strips. A smaller amount 

 of garnet gneiss is also interbanded with these. The banding some- 

 times varies a little in its strike, due to minor, gentle folding (see 

 figure i6), but in general holds the north-northwest course common 

 to this portion of the sigmoid flexure. The streaks and belts of 

 hornblende schist are intersected at numerous places by irregular 



^'O.^-^'-V^'^- 



/ I ~/ \ 



Fig. i6 Minor undulations without intense crenulations at west point of 

 flexure of sigmoid. These are analogous to those pictured in plate 14, lower 

 figure, though less minute. Pegmatite accumulates at the points of separation 

 of the amphibolite xenoliths, but grades into normal fine-grained almost aplitic 

 granite within the distance of a few inches. Former inclusions are now- 

 represented in some cases by streaks of black minerals (chiefly hornblende) 

 resembling schlieren. (a) Granite grading into pegmatite, and carrying thin 

 streaks or larger inclusions of (b), amphibolite. Folded inclusion about 

 5 inches thick. Left is north, right is south. 



Knoll one and one-tenth miles northeast of fork in road north of North 

 Russell. 



masses or '' flammen " of pegmatite, which ordinarily follow the 

 color banding of the rock, that is, the curvature of the flexures, and 

 grade into an aplitic or fine-grained granite identical with that pro- 

 ducing the injection phase elsewhere. Both of these rocks and also 



