Metamorphic 1

Question 1

Metamorphic Rocks

Answer 1

limestone- heat- marble
shale- heat+pressure- slate/schist/gneiss
sandstone- heat- metaquartzite
shale- heat- spotted rock/ hornfels

Question 2

Heat

Answer 2

deep internal heat caused by radioactive decay
heat generated by pressure
heat from molten magma

Question 3

Pressure

Answer 3

lithostatic- created by the weight of rock
lateral- created by tectonic movement

Question 4

Types of Metamorphism

Answer 4

contact- around intrusion
regional- plates colliding
dynamic- around a fault zone

Question 5

Regional Metamorphism

Answer 5

slate- low grade, partially crystalline, fine, dark grey/green, quartz+chlorite, shows slaty cleavage
schist- medium grade, garnet, porphyroblasts, mica, quartz, shows schistosity
gneiss- high grade, layers of colours, crystalline, coarse, orthoclase, biotite, quartz, shows gneissose foliation or monomineralic bonding

Question 6

Contact Metamorphism

Answer 6

metaquartzite- crystalline, medium, granoblastic, quartz, >5.5
marble- crystalline, medium, granoblastic, calcite, <5.5
spotted slate- low grade, partially crystalline, chaistolite andalusite, recrystallised clay, porphyroblasts
hornfels- high grade, cordierite (black), iron in clay, andalusite (white), no iron