metamorphic rocks Flashcards
two metamorphic rocks
marble - Connemara, co.galway
quatzite - mount errigal, co.donegal
what is metamorphism
the changing of rock by the action of great heat and/or pressure
when does metamorphism occur
temperatures higher than 200*C and pressure higher than 300 megapascal
why do rocks experience these high temperatures and pressure
as they become buried deep in the earth
why does burial of rock occur
as a result of tectonic processes such as tectonic plate collision and subduction
what are the 3 types of metamorphism
thermal
dynamic
regional
when does thermal metamorphism occur
when rock are affected by the great head supplied by magma moving deep inside the earths crust
what is an example of this
quartzite - sugarloaf mountain, co.wicklow
when does dynamic metamorphism occur
when rocks are changed by great pressure due to plate movements and along fault lines
what is an example of this
slate - valentia, co.kerry
when does regional metamorphism occur
where rocks are changed by both heat and pressure
what is an example of this
gneiss
what does metamorphism have
several important effects on rocks
what does it cause
foliation and changed their hardness and colour
what does folaition mean
the mineral grains or crystals are flattened and rearranged into thin bands due to the great pressure upon them e.g. gneiss
