556 



GIL VIE 

 Table XIV. 



Analyses of Boothbay Rocks. 





I. 



II. 



III. 



IV. 



V. 



VI. 



VII. 



VIII. 



IX. 



X. 





% 



% 



% 



% 



% 



% 



% 



% 



% 



% 



Si0 2 



67-59 



67.04 



63-44 



56.72 



58-74 



59-64 



55-17 



49.00 



53-oi 



37-4i 



A1 2 3 



17.41 



11.40 



18.84 



15.06 



14.61 



14.76 



18.01 



15.46 



15-54 



2.18 



F 2 3 



•15 



.78 



.16 



i-73 



.48 



•41 



.08 



2.58 



1.85 



3-64 



FeO 



2.98 



3-75 



4-05 



6-33 



3-7° 



3-57 



5-4i 



7.98 



6.09 



3-46 



MgO 



1.40 



3-52 



1.99 



2.58 



5-47 



5-53 



5-29 



6.46 



7.70 



41.08 



CaO 



3-°5 



7.60 



4-23 



6.61 



3-34 



3-i7 



5-64 



11.83 



10.60 



none 



Na 2 



4.89 



2.70 



4-35 



4-73 



5-7° 



3-27 



2.12 



2-75 



2-37 



•54 



K 2 



2-59 



1. 00 



2.07 



.69 



3-79 



6.69 



5.48 



•44 



.62 



.41 



C0 2 



none 



none 



none 



none 



none 



none 



none 



none 



none 



2.03 



H 2 + 



.18 



.16 



■33 



•51 



•27 



.14 



.29 



.09 



•73 



8.84 



H 2 0- 



.04 



.09 



.06 



-15 



•17 



■°3 



.01 



.07 



•47 



.09 



Ti0 2 



•83 



1.68 



1. 41 



4.04 



1.87 



2. 11 



2-33 



3-72 



1.70 



.12 



p 2 o 5 



.19 



.12 



•32 



.40 



1. 00 



.60 



•25 



•3° 



trace 



.08 



MnO 



n. d. 



n. d. 



n. d. 



•35 



n. d. 



n. d. 



n. d. 



n. d. 



n. d. 



.i6Cr 2 5 



Total 



101.30 



99.84 



101.25 



99.91 



99.14 



99.92 



100.86 



100.68 



100.68 



100.04 



I. Grano-lassenose, I. 4. 2. 4. 



II. Meta-grano-sitkose, II. 3. 3. 

 III. Grano-tonalose, II. 4. 3. 4. 

 IV. Placerose, II. 4. 3. 5. 



V. Umptekose, II. 5. 1. 4. 



VI. Meta-monzonose, II. 5. 2. 3. 



VII. Lincolnose, II. 5. 3. 2. 



VIII. Meta-auvergnose, III. 5. 4. 3. 



IX. Auvergnose, III. 5. 4. 3. 



X. Dunose, V. 1. 1. 1. 



METAMORPHISM. 



Since unaltered dikes and metamorphic masses are clearly 

 derived from the same magma, it becomes possible to estimate 

 'the kind and amount of alteration that has taken place in the 

 metamorphic types. A comparison of the mode with the norm 

 among all of the preceding metamorphic types brings out the fact 

 that the difference between mode and norm is of a constant 

 character, and that it is closely similar to the difference between 

 the auvergnose dike and the meta-auvergnose. The presence 

 of titanite seems to be an invariable character of the unaltered 

 mode. 



The following are the essential chemical differences between 

 mode and norm in the metamorphic rocks: 



