234 C. J¥. Fenner — Crystallization of a Basaltic Magma. 



of crystallization was carried, together with the other disturb- 

 ing factors, resulted in an entirely new chemical arrangement. 

 The olivine molecules which were resorbed thereby lost their 

 entity, being distributed among other compounds in a manner 

 which cannot be completely followed, and olivine as such did 

 not reappear among the products of crystallization. 



The fact that remnants of the olivine persist is due to lack 

 of time given for resorption before increasing viscosity put an 

 end to the process. Under somewhat different conditions, 

 easily conceived, the less complete resorption of a mineral 

 would be attended by the formation of reaction rims, or 

 replacement by an aggregate of other minerals ; or its slow 

 solution in a magma in which crystallization was far advanced 

 would constantly change the composition of the mother-liquor, 

 with consequent displacements of equilibria. In the case 

 studied the resorption or solution was nearly complete before 

 the second period of crystallization began, and the effect as 

 regards complexity of results was almost a minimum. 



Petrographic Laboratory, 



Columbia University, 



Nov., 1909. 



