76 BULLETIN 61, U. S. DEPARTMENT OF AGEICULTURE. 



Table X. — Composition of rocks of basin region.'^ 



Constituent. 



Gran- 

 ite 



(av. of 

 113 



analy- 

 ses). 



Rhyo- 

 lite 



(av. of 

 103 



analy- 

 ses). 



Ande- 



site 

 (av. of 



131 

 analy- 

 ses). 



Dacite 

 (av. of 



44 

 analy- 

 ses). 



Diorite 

 (av. of 



85 

 analy- 

 ses). 



Dia- 

 base 



(av. of 

 19 



analy- 

 ses). 



Basalt 

 (av. of 



110 

 analy- 

 ses). 



Sand- 

 stone 

 (av. of 



55 

 analy- 

 ses). 



Lime- 

 stone 

 (av. of 



29 

 analy- 

 ses). 



Shales 

 (av. of 



16 

 analy- 

 ses). 



SiOo 



Per ct. 



66.64 



14.76 



1.62 



1.72 



1.51 



2.74 



3.48 



4.04 



.38 



1.11 



.42 



.03 



.16 



.12 



.04 



.05 



.74 



.03 



.02 



.32 



Tr. 



.07 



Per ct. 



71.55 



13.90 



1.20 



.94 



.60 



1.56 



3.23 



4.17 



.52 



1.71 



.30 



.03 



.13 



.09 



.03 



.04 







Per ct. 



61.29 



15.16 



2.71 



2.86 



2.99 



4.84 



3.30 



2.93 



.63 



1.42 



.56 



.02 



.26 



.15 



.05 



.09 



.07 



.08 



Per ct. 



65.31 



15.37 



2.45 



1.13 



1.34 



3.35 



3.55 



2.85 



1.18 



2.29 



.53 



.01 



.15 



.09 



.04 



.05 



.02 



.18 



Tr. 



.07 



.04 



(?) 



Perct. 



58.84 



16.06 



1.97 



3.79 



3.93 



6.27 



3.62 



2.17 



.25 



1.31 



.67 



.01 



.22 



.08 



.03 



.08 



.16 



.03 



Perct. 



52.04 



15.89 



2.48 



6.84 



5.95 



8.43 



3.20 



.98 



.47 



2.17 



1.06 



.00 



.23 



.16 



.01 



.09 



Per ct. 



51.29 



15.65 



3.10 



5.98 



8.37 



8.78 



2.81 



1.26 



.74 



1.78 



1.01 



.01 



.37 



.08 



.04 



.11 



.08 



.05 



Per ct. 

 70.55 

 5.80 

 1.06 

 2.53 

 1.16 

 5.33 

 1.82 

 1.32 



2. 90 



.39 



Per ct. 

 8.82 



.89 



1.01 

 3.58 

 44.35 



.51 

 1.17 



Perct. 

 54.32 



AI2O3 



14.54 



Fe203 



2.23 



FeO 



2.81 



MgO 



3.18 



CaO 



4.47 



NaoO 



1.65 



K2O 



2.11 



H0O-. 



1.74 



H-0+ 



3.44 



TiO« 



.62 



Zr02 





P2O5 



.17 



.13 



.17 



BaO 



.08 



SrO 









MnO 





1.14 



.37 



S 





CI 











F 











CO2 





.56 

 Tr. 

 .03 



.5i 





.49 



6.74 



38.40 



7.93 



Li20.. . . 





SO3 









.17 





.34 















100.00 



100.00 



100.00 



100.00 



100.00 



100.00 



100.00 



100.00 



100.00 



100.00 



1 Compiled from: Vol. I, Fortieth Parallel Survey, Bui. No. 419, U. S. Geol. Siurvey; Monographs I and 

 XI, U. S. Geol. Survey; Bui. No. 491, Data of Geol. Chemistry, U. S. Geol. Survey. 



