110 GEOLOGY OF THE YELLOWSTONE NATIONAL PARK. 



Table VI. — Mineralogical variation among the diorites of Group lib. 



,a 



3 

 p 



n 

 © 



a 



*o 



p. 



03 



o 

 ® 



s'3 



Amount of quartz. 



Relative amount of pyroxene and 

 hornblende. 



Relative amount of pyrox- 

 ene, hornblende, and bio- 

 tite. 



Little. 



Mod- 

 erate. 



Con- 

 sider- 

 able. 



Much. 



P- 



P>h. 



p=h. 



p<h. 



h. 



iph). 



1 

 (ph)>b. (ph)=b 



1 



(J>h)<b. 



301 

 302 

 303 

 301 

 305 

 306 

 307 

 308 

 309 

 310 

 311 

 312 

 313 









301 

 302 

 303 













301 

 3D9 



.... 



301 

 3 























■)■} 





65.60 















303 



303 





304 













304 

 305 

 306 

 307 

 308 





304 



65.94 





305 

 306 

 307 

 308 



39 

 310 

 311 



12 

 313 













.... 



305 

















306 



63.78 

















.... 



307 

 3 

















58 

 309 

 310 

 311 



12 





64.07 





3 









*309 









+ 310 











65.11 













311 

 312 











3 















3 



64.85 













313 



.... 



313 



















* This rock belongs with 288, resembles it in structure and character, but is higher in silica and feldspar. 

 t An exceptional variety, from talus. 



Table VII. — Mineralogical variation among the diorites of Group lie. 



u 



© 



P 



a 



.! 



© 

 P. 



O 



M 



<s ta 



o 



9 



ft 



Amount of quartz. 



Relative amount of pyroxene and 

 hornblende'. 



Relative amount of pyrox- 

 ene, hornblende, and bio- 

 tite. 



Little. 



Mod- 

 erate. 



Con- 

 sider- 

 able. 



Much. 



P- 



P>h. 



P~h. 



P<h. 



h. 



(ph). 



(ph)>b. 



(ph=b.) 



(ph)<b. 



314 



315 



316 



317 



318 



319 



320 



321 



286a 



275a 



322 



323 











314 



315 



316 



317 



318 



319 



320 



321 



286a 



275a 



322 



323 



"3 

 315 

 316 



14 













3 



14 

 315 

 316 



318 

 319 

 320 

 321 

 286a 

 275a 

 322 

 !3 











































65.48 

 65.80 













3 

 318 



7 



.... 



3J7 

























319 





























320 

 321 









67.54 



































28 























275a 

























322 

 323 









66.05 





















3: 

























* The first six rocks in this group are closely related to the main mass of the diorite of Group 11a. 



