Although muscovite, feldspar and quartz are not considered useful ...

[misspop]

Although muscovite, feldspar and quartz are not considered useful as index minerals, which of the following situations could be useful in determining the grade of metamorphism in a region?
 
  A) the coexistence of muscovite, feldspar and quartz
  B) the disappearance of rocks containing muscovite and quartz
  C) the coexistence of feldspar and quartz
  D) the disappearance of rocks containing quartz

Question 2

If a rock containing kyanite, sillimanite, and andalusite were to undergo an increase in pressure, what must happen to temperature in order for that rock to continue to have stable kyanite, sillimanite, and andalusite?
 
  A) temperature must increase
  B) temperature must decrease
  C) temperature must stay the same
  D) It is impossible for it to continue to have stable kyanite, sillimanite, and andalusite.

[vboyd24]

Answer to Question 1

Answer: B

Answer to Question 2

Answer: D

[misspop]

Thanks for the timely response, appreciate it

[apple]

Gracias!