Origin Metamorphic rocks arise from the transformation of existing rock types Process called metamorphism, which means "change in form". The original rock is subjected to heat and pressure, causing profound physical and/or chemical change Formation zone (ratio of heat and pressure) upper zone - epizone middle zone - mezozone lower zone – katazone Types of metamorphism Regional metamorphism -- affects a large area; commonly due to mountain building; foliated rocks common Contact metamorphism -- rocks near igneous intrusion get baked; produces non-foliated met. Rocks

EPIZONE P – decisive, thin 1-2mm slak texture, directional texture: clay shale, phyllite, talk schist MEZOZONE P – T equaly decisive, thick >2mm slak texture, directional texture: schist (mica) KATAZONE T – decisive, thin 1-2mm slak texture, directional texture: clay shale, phyllite, talk schist

EPIZONE Clayslate: composed clay minerals and quartz grains and the typical color is gray. Water resistrant. Phyllite: foliated metamorphic rock created from slate that is further metamorphosed so that very fine grained white mica achieves a preferred orientation. Typicaly black, dark gray, thin slated (mm), shiny

EPIZONE Greenschist: green minerals such as chlorite, serpentine and platy minerals such as muscovite and platy serpentine, thin slated (mm),

EPIZONE Talc schist: soft, talc mineral. Light coloured Serpentinite: - green – black -Serpentine mineral, quartz, calcite, pyrite -can be polished -strong

MEZOZONE Schist (mica) - sparkles (mica content), grey - biotite, muscovite, feldspar, quartz - local building material

KATAZONE Gneis: - looks like granite, BUT: - directional terxture - minerals: quartz, feldspar, plagioclase, biotite, amphibole Crystaline texture, measonary stone, load bearing structure, ornamental stone, crashed stone (ballast under rails, roads, concrete agregate)

KATAZONE Marble Crystaline texture, any colour (bright), Fizzles to acids Calcite veins, fells colder than limestone (becouse wery dense) Load bearing structure, Ornamental stone, chemistry