How could a researcher use magmatic differentiation to determine ...

[D2AR0N]

How could a researcher use magmatic differentiation to determine if a batholith is the result of one body of magma cooling and crystallizing or multiple bodies of magma?
 
  What will be an ideal response?

Question 2

In the process of a magma cooling and crystallizing, if the original melt contained large amounts of iron, why isn't quartz a ferromagnesian mineral?
 
  What will be an ideal response?

[tashiedavis420]

Answer to Question 1

Answer: Bowen's reaction Series dictates that a single suite of silicate minerals can form from one cooling magma. So, within one body of magma, one should find the ferromagnesian minerals concentrated toward the bottom and the felsic minerals toward the top. If, after encountering the felsic minerals, one finds another concentration of ferromagnesian minerals above them, it likely represents the bottom of a different body of magma that went through a separate period of crystallization.

Answer to Question 2

Answer: As a magma begins to crystallize, early-forming minerals like olivine will remove iron from the melt and lock it away in solid crystals, thus preventing later minerals from using iron in their molecular structures.