gel 1 - week 7

protolith

the parent rock

metamorphism

shape-shifting without melting

recrystallization

same mineral, new shape

phase change

same ingredients, new structure

neocrystallization

brand new minerals grow

pressure solution

dissolves under squeeze

plastic deformation

stretches like goo

metamorphic heat limit

always below the melting point

mineral survival recipe

temperature, pressure, plus water

differential stress

squeezed unequally from sides

foliation

visible, striped layering

foliated progression

slate → phyllite → schist → gneiss

non-foliated duo

quartzite and marble

pelitic

mud-rich clay parentma

fic

dark volcanic parent

calcareous

lime-rich shell parent

quartzo-feldspathic

light granite parent

contact

baked by nearby magmab

burial

squeezed deep under sedimentdy

dynamic

ground up along faults

regional

smashed by mountain collisions

hydrothermal

cooked by hot ocean water

subduction

high pressure, low temperature

shock

blasted by meteorite impacts

metamorphic grade

scale of cooking intensity

hornfels

baked hot and dry

bleuschist

cold trench squeeze

exhumation

return to the surface

index minerals

geological temperature gauges

prograde

getting hotter and deeper

retrograde

cooling down, needs water