Metamorphic rocks Flashcards
what is metamorphesis?
biological transformation
what is a protolith?
a parent rock, either igneous or sedimentary
when does metamorphism occur?
when a protolith is exposed to heating
squeezing
hot fluids
how does temperature and pressure affect metamorphic grade?
the higher the P/ T the higher the degree of metamorphism
when does metamorphism occur at low pressure?
200-850 degrees celcius
when does a rock metamorphize under regular condition?
more than 8km deep and over 200 degree c
what is contact metamorphism?
when the rock surrounding hot magma is baked
how does water affect metamorphic reaction?
it speeds them up by bringing ions to the system
what do hydrothermal fluids contain?
elements that migrated out of magma
what is hydrothermal metamorphism?
when water is the main agent of metamorphism
what is lithostatic stress?
when the pressure on a rock is equal on all sides
what is directed stress?
pressure is higher in one direction
what is the result of directed stress
large areas of regional metamorphism
what happens to regional metamorphic rocks?
the become folded from direct pressure
methods of metamorphic heating?
contact metamorphism
