THE BEHAVIOR OF INCLUSIONS IN IGNEOUS MAGMAS 535 



state it as a general law therefore that a saturated liquid in any sys- 

 tem dominated by reaction series will not remain indifferent to 

 inclusions even of the exact composition with which it is in equilib- 

 rium, and that the effect of the addition of such inclusions is a 

 tendency to limit the scope of the crystalline products to adjacent 

 members of the reaction series involved. 



Let us now examine what happens when inclusions of an early 

 member of a discontinuous reaction series (or reaction pair) are added 



Fig. 8. — Equilibrium diagram of the system anorthite-forsterite-silica. (After 

 Andersen.) 



to a liquid saturated with a later member. The liquid F is just 

 saturated with clino-enstatite at 1450°. If it is cooled, clino- 

 enstatite will separate first, it will later be joined by siUca and then 

 by anorthite, when the whole mass will solidify at 1222". But if 

 inclusions of forsterite are added to this liquid it will instantly start 

 to react with these inclusions and make them into the mineral with 

 which it is saturated, viz., cHno-enstatite. If there is perfect oppor- 

 trniity for reaction we may readily predict what the end result will 

 be for varying amounts of added inclusions. 



