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Metamorphic rock. Origin Metamorphic rocks arise from the transformation of existing rock types P rocess called metamorphism, which means "change in form". The original rock is subjected to heat and pressure, causing profound physical and/or chemical change
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Metamorphicrock Origin Metamorphic rocks arise from the transformation of existing rock types Processcalled metamorphism, which means "change in form". The original rock is subjected to heat and pressure, causing profound physical and/or chemical change Formationzone(ratio of heat and pressure) upperzone - epizonemiddlezone - mezozone lowerzone – 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
Metamorphicrock EPIZONE P – decisive, thin 1-2mm slaktexture, directionaltexture: clayshale, phyllite, talkschist • MEZOZONE • P – T equalydecisive, thick >2mm slaktexture, directionaltexture: schist (mica) • KATAZONE • T – decisive, thin 1-2mm slaktexture, directionaltexture: clayshale, phyllite, talkschist
Metamorphic rock EPIZONE Clayslate:composed clay minerals and quartz grains and the typical color is gray. Waterresistrant. Phyllite: foliated metamorphic rock created from slate that is further metamorphosed so that very fine grained white mica achieves a preferred orientation . Typicalyblack, darkgray, thinslated (mm), shiny
Metamorphic rock EPIZONE Greenschist: green minerals such as chlorite, serpentine and platy minerals such as muscovite and platy serpentine, thinslated (mm),
Metamorphic rock EPIZONE Talcschist:soft, talcmineral. Lightcoloured Serpentinite: - green – black -Serpentinemineral, quartz, calcite, pyrite -can be polished -strong
Metamorphic rock MEZOZONE Schist (mica) - sparkles (micacontent), grey - biotite, muscovite, feldspar, quartz local building material
Metamorphic rock KATAZONE Gneis: - lookslikegranite, BUT: - directionalterxture- minerals: quartz, feldspar, plagioclase, biotite, amphibole Crystalinetexture, measonarystone, loadbearingstructure, ornamentalstone, crashedstone (ballastunderrails, roads, concreteagregate)
Metamorphic rock KATAZONE Marble Crystalinetexture, anycolour (bright), Fizzlestoacids Calciteveins, fellscolderthanlimestone (becousewerydense) Loadbearingstructure, Ornamentalstone, chemistry