46 



NEW YORK STATE MUSEUM 



Na^O 



K2O . 



H2O + 



H2O— 



H2O 



TiO^ 



P2O5 



MnO 



BaO 



S 



CO2 .. 



I 

 3-50 

 5-90 



2 



436 

 5-66 



40 



77 



•03 

 .10 

 •05 



.07 



3 4 



2.21 5-06 



3-63 5-15 



• 75 



.18 



30 



07 



• 25 



tr 



13 



.12 



•58 



5 

 3-09 



4-25 



41 



6 7 



68 5-31 

 90 4.14 



49 



08 



52 



09 



100 -22 100. I( 



99.49 99-73 100.09 100.10 100.23 



W. 



1 Quartz-augite syenite. Altamont, Franklin co. Analyzed by E 

 Morley for H. P. Gushing. N. Y. State Mus. Bui. 115. 1907. p. 514. 



2 Augite-syenite. Little Falls, Herkimer co. Idem. 



3 Syenite, gneissoid. Whitehall, N. Y. Analysis by W. F. Hillebrand. 



4 Augite-syenite. Loon Lake, Franklin co. Analyzed by E. W. Morley 

 for H. P. Gushing, who considers the occurrence as typical. Geol. Soc 

 Am. Bui. 10. 1900. p. 177. Revised in N. Y. State Mus. Bui. 115. 1907 



P- 514 _ _ 



5 Augite-syenite. Tieonderoga, Essex co. Analysis by M. K. Adams. 



6 Augite-syenite. Altamont, Fronklin co. Analyzed by E. W. Morley 

 for H. P, Gushing, as under no. i. 



7 Augite-syenite. Line of townships 22 and 23. Franklin co. Analyzed 

 by E. W. Morley for LI. P. Gushing, as under no. i. 



In the quantitative system, nos. i and 2 fall under class I Persa- 

 lane ; order 4 Brittannare ; rang 2 Toscanase ; subrang 3 Toscanose. 



Nos. 3 and 5 belong in class II Dosalane ; order 4 Austrare ; 

 rang 2 Dacase ; subrang 3 Adamellose. 



No. 4 is in class I Persalane; order 5 Canadare; rang 2 Pulas- 

 kase; subrang 3 Pulaskose. 



No. 7 is in the same except the subrang 4 Laurvikose. 



No. 6 is in Class II Dosalane ; order 4 Austrare ; rang 3 Ton- 

 alase ; subrang 3 Harzose. 



Under the microscope the chief feldspar is at once seen to be 

 microperthitic orthoclase ; that is, the orthoclase of the ordinary 

 syenites is filled with flattened, parallel blades or spindles of albite. 

 This microperthite is very characteristic and with the beautifid 

 emerald-green pyroxene afifords one of the distinguishing features 

 of this group of rocks. Plagioclase is not entirely lacking, and es- 

 pecially in the specimens from Mineville is at times quite prom- 

 inent. Quartz is variable. As will be shown later there are phases, 

 apparently differentiation products of the syenite magma, in which 



