1 82 



NEW YORK STATE MUSEUM 



able amount of FeO, indicating the presence of an unusual amount of 

 siderite. Moreover, in the latter case, the total amount of silicate 

 is small and tends to exaggerate any errors in the combinations 

 assumed. 



In spite of these difficulties, however, the agreement of the ferrous 

 silicate composition is fairly close, both for the two samples them- 

 selves and for the preceding oolites. Allowing for errors in making 

 the combinations, for the somewhat heterogeneous character of the 

 rocks and, even more, for the uncertain and variable nature of the 

 minerals concerned, the agreement is, on the whole, as good as could 

 be expected and quite sufficient to justify the conclusion that the 

 ferrous silicate of the green and the red oolites is essentially the same 

 as that of the gray oolite and is, therefore, chamosite or a closely 

 related mineral. 





9 (G 



reen) 



10 (Red) 



ga 



10a 





Sol. 



Insol. 



Sol. 



Insol. 



(37-23%) 



(22.07%) 



Si0 2 



9-51 

 7.07 



3 o7 



13-82 



2-35 

 22.33 



O.II 

 O.IO 



4.48 



0.31 



1592 



0.05 



1. 17 



0.56 



0.00 

 0. 17 



8.03 

 0.00 

 6.69 

 0.00 

 0.13 

 0.24 

 0.16 

 0.03 



0. 12 

 0.13 

 529 

 0.00 



5-45 



4-94 



H-59 



29.64 



i-39 



12.35 



0.18 



0.15 



2-43 

 0.17 



22.78 

 0.01 

 0.97 



0.94 

 0.03 

 0.05 



5-73 

 0.13 

 0.41 

 0.00 

 0.06 

 0.13 



J 0.03 



0.01 

 0.04 

 0.02 

 0. 12 



25-54 

 18.99 



37-13 

 6.31 



12.03 



24.70 

 22.39 



M203 



Fe 2 3 



FeO 



41.90 



MgO 



CaO 





Na 2 









K 2 





H2O+ 



11 .01 



H2O— 





CO2 





Ti0 2 





P 2 5 





S 





MnO 





BaO 





SrO 











79.71 



20.82 



93-07 



6.86 



100. 



1 00.0 





100 



•53 



99-93 







9 Green oolite, Clinton, N. Y. Princeton Catalog no. 61 10. E. W. Morley 

 analyst. 



10 Oolitic ore, Clinton, N. Y. Princeton Catalog no. 61 11. E. W. Morley, 

 analyst. 



ga Ferrous silicate of green oolite. 

 - 10a Ferrous silicate of oolitic ore. 



