ASA EDSON S. BASTIN 
I II 
DIABASE HORNBLENDE SCHIST 
Per cent. Mol. Prop. Per cent. Mol. Prop. 
SiO wees eee 47-45 -791 49.78 .830 
IN AO Peo nhs sie 14.83 -I45 ingle) .128 
He7 OR perdenseien: an AT, .O16 Ale Bis .027 
He Onteniente TAAL . 204 THE AA . 163 
Mig Osea 5.00 e025 5-40 Blois 
CaO Tera ess: 8.87 .158 8.92 .159 
IEA O), ate pie 2.97 .048 2.30 .039 
KOM caus eek 0.99 .OII TOS .OIL 
1S O ey eee rea ae I.00 ae I.14 Haves 
API OW aces I.47 .O19 2.22 028 
COR see 0.36 ate o.1I0 Aus 
Mir @ eras errs ey meres 0.27 004 
ahotalsieer : 100.12 Sse 100.46 
Norm of I Norm of IT 
Quartz 2.76 
6.12 | Orthoclase 6.12 coe Care 
Salic aa55 aro 25nL Sleubite 20.44.| 97° ie 
23.91 | Anorthite 21.68 
2.89 | Ilmenite 4.26 
3.71 | Magnetite 6.26 : 
Femic 43.69 ( 16.89 | Diopside EIS.08 geieso) Istoiunle 
2.38 | Hypersthene 19.00 
17.82 | Olivine 
Both rocks fall in class III, order 5, rang 3, and sub-rang 4, 
Camptonose.* 
It will be seen therefore that, in spite of complete recrystallization, 
of complete change in texture, and of notable change in mineral com- 
position, the chemical makeup of the rock has suffered little change. 
A few other examples similar to those cited above are available 
in geologic literature and might be quoted if space permitted. The 
mass of chemical data, however, bearing on the metamorphism of 
igneous rock is regrettably small and the field is one of the most promis- 
ing for geologic investigation. 
In the opinion of the writer the data cited above show that in 
many cases perfect parallel structures have been developed in igneous 
« Two changes are worthy of note in passing: first, the appearance of quartz both 
in the norm and the mode of the schist, and second, the change of some of the iron from 
the ferrous to the ferric state. 
