Why is sedimentary rock converted into metamorphic rock?

Answer 1

Sedimentary rock is formed generally at low temperature and pressure conditions.Therefore a change in this conditions to higher levels triggers mineralogical change.The driving forces for metamorphism are changes in temperature, pressure,

and composition of the environment or strong deformation.These changes

cause recrystallization in the solid state as the rock changes toward

equilibrium with the new environment.Hence, formation of metamorphic rocks.

Answer 2

Heat, Pressure or Stress.