Question

13. True or False: Different metamorphic rocks may form with the same metamorphic grade.

A. True

B. False

14. Metamorphism along convergent boundaries between two continental plates is defined by:

A. low temperature and pressure.

B. high temperature and pressure.

C. low temperature and high pressure.

D. high temperature and low pressure.

15. What type of metamorphic rock would result from the complete melting of gneiss?

Answer 1

1)metamorphic Grade = change of metamorphic rock with parent rock.

parent rock temperature=150c to 300c implies very low grade example:slate

parent rock temperature=300c to 450c implies low grade example:phyllite and marble.

parent rock temperature=450c to 550c implies medium-grade example: schist and quartzite.

so statement 1 is true.

2)Mostly regional metamorphism occurs at convergent plate boundaries. Regional metamorphism occurs at high pressure and temperature. so answer B is correct for convergent boundaries between two continental plates.

3. partially melted gneiss causes migmatite (metamorphic), more intense heat produces paragneiss (metamorphic and answer to the question) and completely melted becomes igneous rock magma solidified called plagiogranite(igneous).