326 WATSON AND CLINE IGNEOUS DIKES IN VIRGINIA 



analyses of three related rocks in columns II, III, and IV. It will be 

 seen that the rocks have in general similar features of chemical composi- 

 tion, and, as shown below, except II, they have the same position in the 

 quantitative system and are designated by the same subrang name, ourose. 



Analyses of Camptonite and related Rocks 



I 



la 



II 



III 



IV 



43.26 



.721 



41.94 



43.74 



42.46 



14.01 



.137 



15.36 



14.82 



12.04 



7.17 



.045 



3.27 



2.40 



2.19 



5.41 



.075 



9.89 



7.52 



5.34 



5.57 



.139 



5.01 



6.98 



12.40 



10.09 



.180 



9.47 



10.81 



12.14 



2.83 



.045 



5.15 



3.08 



1.21 



3.78 



.040 



0.19 



2.90 



2.68 



0.49 

 2.74 



.023 



3.29 



2.94 



4.03 



1.81 



4.15 



2.80 



2.47 



1.18 



.008 





0.64 



0.84 



0.34 



.005 



0.25 





0.16 



0.21 



.006 





0.10 





1.57 





2.47 

 100.44 



1.50 

 100.23 



0.55 



100.46 





99.51 



ablende- 



basalt) 



from Mossy Cr 



eek, Augusta 



Si0 2 . 

 A1 2 3 

 Fe 2 3 

 FeO . 

 MgO . 

 CaO . 

 Na 2 . 

 K 2 . . 

 H 2 0— 

 H 2 + 

 Ti0 2 . 

 P 2 5 . 

 MnO . 



S 



CO., .. 



I. Camptonite (analeite 

 County, Virginia. J. Wilbur Watson, analyst. 



la. Molecular ratios from I. 



II. Camptonite from Campton Falls. New Hampshire. G. W. Hawes, analyst 



III. Moncbiquite, Rio do Ouro, Serra de Tingua. Brazil. Hunter and Rosen 

 buscb. Tscbermak's Min. und Petrog. Mittb.. vol. xi. 1890. p. 464. 



IV. Moncbiquite. Willow Creek. Castle Mountains, Montana. Weed and 

 Pirsson, Bulletin 139, U. S'. Geological Survey. 1896, p. 115 





The position of the rock in the quantitative system is indicated in the 

 following computed norm and ratios, which show it to be ourose: 



Norm Ratios 



Or 22.241 Sal 53.08 



An ::::■: hI^ 53 - 08 CIass, ^ = ^ =1 2 = ni > salfemane - 



Ne 8. 52 J 



01 3.38 



Di 22.01 



Mt 10.44 



II 3.50 



L 8.52 

 Order, — = -77-77 = . 1 9 =- 6, portugare. 

 F 44.56 



M2.38 K 2 + Na 2 85 , , 



APJ ™J Rang '-^T- = ^= 1 - 63 - 3 ^' hm ^Si q uase 



H,'-> 8.23 K 2 -40 



100.26 



Symbol Name 



III. 6. 3(2). 3. Ourose (?). 



