What role does fluid play in metamorphism? What will be an ...

[KWilfred]

What role does fluid play in metamorphism?
 
  What will be an ideal response?

Question 2

What grade of metamorphism occurs at a depth of 1 km and a temperature of 75 degrees C?
 
  A) low-grade metamorphism
  B) lithification of sedimentary rocks
  C) medium-grade metamorphism
  D) not found on Earth

[popopong]

Answer to Question 1

Answer: Fluids, present in the original rock or introduced from magma or high-temperature dehydration and degassing reactions, create metamorphic minerals that incorporate components from the fluid molecules. Metamorphic reactions take place faster and at lower temperature in the presence of water than they do under dry conditions. The movement of fluid during metamorphism delivers some ions and removes others, so that the metamorphic rock has a different bulk composition than that of the parent rock.

Answer to Question 2

Answer: B