314 



F. BASCOM — PIEDMONT DISTRICT OF PENNSYLVANIA 



Determination of the rock species represented by the gabbro mass 





I. 



II. 



III. 



IV. 



V. 



VI. 



Si0 2 . . . . 



58.57 



55.16 



54.03 



53.21 



48.02 



44.04 



A1 2 3 . . . 



16.10 



17.51 



16.71 



1.94 



20.01 



20.01 



Fe 2 3 . . • 



2.89 



2.62 



1.37 



1.44 



1.13 



4.22 



FeO.... 



6.12 



5.83 



7.70 



7.92 



7.29 



8.61 



MgO.. . . 



2.33 



4.35 



5.66 



20.78 



10.05 



5.01 



CaO. . . . 



7.39 



8.50 



8.84 



13.12 



11.42 



11.68 



Na a O... 



2.11 



1.83 



2.99 



0.11 



0.51 



1.24 



K 2 0.... 



1.01 



1.08 



0.67 



0.07 



0.05 



0.15 



H 2 0+.. 



1.27 



2.01 



0.53 



0.87 



0.57 



1.90 



H 3 0— .. 



0.21 



0.21 



0.14 



0.14 



0.10 



0.11 



C0 2 



None. 



None. 



0.40 



0.10 



0.25 



None. 



Ti0 2 . . . . 



1.41 



0.64 



0.84 



0.26 



0.23 



2.24 



Zr0 2 . . . . 



0.09 



0.02 



Not est. 



Trace. 



None. 



0.10 



PA..» 



0.37 



0.21 



0.13 



Trace. 



Trace. 



0.52 



Cl 



None. 



Not est. 



Not est. 



Not est. 



Not est. 



Not est. 



F 



Not est. Not est. 



Not est. 



Not est. 



Not est. 



Not est. 



FeS 2 .... 



Trace. 



0.03 (.025) 



Not est. 



0.03 



0.11 



0.25 (.1355) 



S 



Trace. 





0.09 









Cr 2 3 ... 



None. 



Trace. 



Trace. 



0.20 



0.03 



None. 



NiOCoO 



None. 



0.01 



Trace. 



0.03 



0.01 



0.01 



MnO... 



0.18 



0.05 



0.13 



0.22 



0.18 



0.28 



BaO. . . . 



Trace. 



Trace. 



Trace. 



None. 



None. 



None. 



SrO 



Trace. 



Trace. 



Trace ? 



None. 



None. 



None. 



Li 2 0. . . . 



Trace. 



Trace. Faint trace, 





.... 



Trace. 



v 2 o 8 .... 



0.02 (.018) 0.04 (.036) 





0.03 



0.02 



0.05 



Total. 



100.07 



100.17 



100.23 



100.42 



99.98 



100.42 







Norms 













I. II. 



III. 



IV. 



V. 



VI. 



Quartz . . . 





21.78 13.56 



4.56 



.... 



0.60 



2.16 



Orthoclase 







6.12 6.67 



3.89 



0.56 



0.56 



1.11 



Albite 





17.82 15.20 



25.68 



1.05 



4.19 



10.48 



Anorthite.. 





31.41 36.42 



30.30 



4.15 



51.99 



48.37 



Zircon. 













0.18 



Diopside. . . 





2.32 4.08 



10.52 



48.21 



3.83 



5.23 



Hypersthei 



ae . . . , 



11.11 16.56 



20.67 



41.98 



35.65 



19.05 



Magnetite . 





4.18 3.71 



2.09 



2.09 



1.62 



6.03 



Ilmenite... 



... ... 



2.74 1.22 



1.52 



0.46 



0.46 



4.26 



Apatite 





1.01 0.34 



0.34 





.... 



1.34 



Pyrite 





0.03 



0.24 





.... 



0.25 



Olivine — 









0.31 







H 2 





1.48 2.22 



0.67 



1.01 



0.67 



2.01 





1 





Tota 



100.97 100.01 



100.48 



100.12 



99.57 



100.47 



