24 NEW YORK STATE MUSEUM 



Ak.03 . 

 Fe^Os . 

 FeO .. 

 MgO . 

 CaO .. 

 Na.O . 

 K.0 .. 

 H.0 + 

 H.O — 

 TiO^ . 

 P2O, .. 

 CI .... 

 F .... 



S 



MnO . 

 BaO .. 



I 



2 



3 



4 



5 



72.41 



73-33 



73.10 



70.13 



1.207 



13.85 



13-55 . 



14.29 



15^47 



.136 



1. 13 



.58 



1.04 



1.52 



.007 



1-57 



1-53 



1.04 



1.05 



.022 



.45 



•45 



•53 



.85 



.011 



1.54 



1.66 



1. 18 



1.60 



.028 



4-31 



5.01 



3.08 



3-72 



.069 



3.68 



3.12 



5.36 



4.39 



.040 



.41 



•45 



•54 

 .07 



.48 

 .01 





•44 



•17 



.18 



•30 



.005 



.07 . 





.03 

 • 03 



.05 



. 0005 



.01 





.02 



.09 



.0005 



• 05 





.02 



.07 





■ 33 



.04 



.07 



.08 



.004 



•03 







•05 





100.28 99.89 100.58 99.86 



1 White granite (Laurentian?) from 2 miles north of Saratoga. E. W. 

 Morley, analyst. 



2 Laurentian granite gneiss from the Methuen bathylith of central Ontario. 

 F. D. Adams, Jour. Geo!., 17:17. 



3 Laurentian granite gneiss of the Alexandria bathylith. E. W. Morley, 

 analyst, N. Y. State Mus. Bui. 145, p. 176. 



4 Laurentian granite gneiss of the Antwerp bathylith of northwestern New 

 York, granite with slight amphibolite contamination. E. W. Morley. analyst, 

 N. Y. State Mus. Bui. 145, p. 176. 



5 Molecular ratios of analysis no. i. 



A comparison of the four analyses given brings out at a glance 

 the practical identity of the Saratoga rock with those of Ontario 

 and northwestern New York. They dififer only in the alkali ratio, 

 soda exceeding potash in the rock from Ontario, and the reverse 

 being true in that from northwestern New York. In this respect 

 the Saratoga rock is more like that from Ontario, though occupying 

 an intermediate position. That this would be the case was indicated 

 in the thin section, oligoclase being much more abundant and 

 microperthite correspondingly less so than in the rocks from the 

 Thousand Islands region. We regard the chemical evidence as 

 strongly corroborative of the impression gained in the field regard- 

 ing the igneous nature of this white gneiss. 



