238 N. L. BOW EN 



"parfois legerement schisteux." 1 It may be noted at this point, 

 also, that an augitite associated with the perfectly massive alkaline 

 types of the Ice River district, British Columbia, is described as 

 having a "suggestion of a schistose texture." 2 Observations such 

 as these, though seemingly unimportant, may nevertheless have 

 considerable importance in connection with the movement of a 

 mass with very little interstitial liquid. It may well be, also, that 

 in the movement of a mass with a small amount of interstitial 

 liquid lies the secret of the formation of some monomineralic 

 masses of extreme purity. Such movement when it caused a 

 crushing of crystals at their points of contact would necessarily 

 imply a flowing away of some liquid. Continuance of this action 

 might, under certain conditions, result in a squeezing out of the 

 interstitial liquid as from a sponge. 



Rocks made up almost exclusively of albite or oligoclase are 

 known, but there is usually evidence, if only of a collateral nature, 

 that solutions have played a prominent part in their formation. 

 Though often occurring as dikes there is never any reason for 

 believing that these materials have ever been molten as such. 

 And so it is with many masses of magnetite, indeed it is not impos- 

 sible that practically any mineral might occur as dikes having a 

 similar character and origin. Such an occurrence need not, how- 

 ever, affect one's belief that, as a rule, monomineralic rocks are 

 crystal accumulations analogous to the great anorthosite masses 

 and having the characteristics corresponding thereto. 



It will be noted that nowhere in the foregoing discussion has an 

 appeal been made to the remelting of the masses of crystals once 

 accumulated. While the writer would not go the length of stating 

 that such action never takes place, he would nevertheless con- 

 sider that it must be of very exceptional occurrence. It has been 

 shown that the monomineralic rocks are best explained without 

 the aid of the doctrine of remelting, and many of the broader 

 generalizations of igneous geology are opposed to it. For example, 

 the parallelism between sequence of intrusion and sequence of con- 



1 "L'Oural du nord I," Mem. soc. phys. et d'hist. nat. de Geneve, XXXIV (1902), 

 Fasc. 2, p. 101. 



2 Warren, Allan, and Conner, Am. Jour. Sci. (4), XLIII (1917), 75. 



