92 NEW YORK STATE MUSEUM 



green and black mottled aspect, and seems certainly secondary 

 and formed during metamorphism. There is considerable magne- 

 tite in the rock, which shows augite rims wherever it is in contact 

 with quartz and also around the small quartz inclusions. A little 

 biotite and gTeen hornblende are present, and considerable apatite,, 

 the latter often of large size and full of black, dustlike inclusions. 

 The feldspar is mostly anorthoclase, though quite a bit of oligo- 

 clase is present. There are some larger feldspars which seem to 

 have escaped recrystallization, and these are microperthite. 

 Quartz is but sparingly present, mostly in coarse leaves, though 

 also as inclusions in the coarse hypersthenes and magnetites. It 

 is present to the amount of some 5^ only, while feldspar consti- 

 tutes from 65^ to 70^. 



The rock seems to be igneous and to be a syenite, though with 

 peculiarities. Except for some possible small amounts of feldspar,, 

 magnetite and apatite, it seems to have undergone complete re- 

 crystallization. In many respects, notably in the augite rims, it 

 is peculiar and affiliated with the ore. 



The last rock of the series strongly resembles the acid variety 

 of the ordinary syenite gneiss of the region. It is mainly a feld- 

 spar quartz rock. In addition are numerous small zircons and a 

 little apatite, biotite, magnetite and hornblende, all together not 

 constituting over 5^ of rock. The feldspar is mostly anorthoclase, 

 though with a little oligoclase in addition. The quartz forms 

 some 20fc of the rock and is mainly in rather coarse leaves. The 

 rock is wholly recrystallized, but has syenite composition. 



We seem here to be clearly dealing with a basic segregation in 

 a rather acid rock of probable igneous origin. But the exposures 

 are so poor, and the whole series so metamorphosed that no de- 

 cisive evidence is forthcoming in regard to the origin of the ore. 

 While it seems not unlikely that it may represent an original 

 basic segregation from the cooling intrusive, analogous to the 

 titaniferous ores of the gabbroic intrusives of the region, the evi- 

 dence is far too meagre to warrant a definite pronouncement in 

 favor of this mode of origin. The ore may equally as well owe its 

 existence to secondary processes. 



