ADIRONDACK MAGNETIC IRON ORES 169 



CaO..' 8.38 



P 2.59 



S 3.12 



99.21 



Iron 40 . 90 



The analysis is perhaps of questionable accuracy in some respects. 

 The sulfur is certainly all combined with the iron to form bisulfid, 

 and the ferrous and ferric oxids can hardly be present in the exact 

 proportions to form magnetite when there is such a large amount 

 of titanium present as ilmenite. That the determinations of iron 

 and titanium are substantially correct as to bulk, however, has 

 been confirmed by an analysis made by Prof. E. W. Morley, on a 

 sample gathered recently from the mine dump. The analysis 

 gave: Fe 50.79 per cent; Ti0 2 9.90 per cent. 



The immediate walls of the deposit are not in evidence, but 

 there are abundant outcrops in the vicinity, all of quartzose gneisses. 

 The latter include a pink, slightly foliated variety and a grayish 

 garnetiferous one. Both show under the microscope a composition 

 that allies them to the granites and granitic gneisses of the Adiron- 

 dacks. The feldspars are chiefly microperthite and microcline, 

 though there may be a little acid plagioclase present. Quartz is 

 abundant. The dark minerals comprise biotite and magnetite 

 and a chloritic product that may have been derived from augite. 



The ore is an extremely dense hard mass in which the magnetite 

 occurs in finely divided particles intergrown with larger grains of 

 pyrite. Biotite and garnet are also present. Some specimens 

 taken from the dump at the shaft show inclusions of a green feld- 

 spar rock resembling the Adirondack syenite in composition and 

 appearance. 



The derivation of the deposit is difficult to explain except that 

 it may be related to some underlying magma from which the ore 

 body represents an offshot, perhaps intrusive in the granitic gneiss. 

 The association of syenite alluded to affords evidence of the exist- 

 ence of such a magma, and it is well known that the gabbros and 

 syenites and the granites in some cases as well grade into each 

 other and are closely connected in their genesis. 



OTHER TITANIFEROUS DEPOSITS 

 In the town of Westport, about 2 miles south of Westport 

 village, several pits have been excavated in deposits that outcrop 



