METAMORPHIC ROCKS Are rocks that have been altered or have undergone change Metamorphic rocks begin as either igneous, sedimentary or another metamorphic rock…we call the beginning (1st) rock the parent rock The parent rock is under tons and tons of pressure, which causes heat to build up, causing the parent rock to SOFTEN or RECRYSTALLIZE and change or “morph” into a metamorphic rock Parent Rock morphs into Metamorphic Rock Granite (Ign) Gneiss Sandstone (Sed) Quartzite Shale (Sed) Slate Parent Rock morphs into Limestone (Sed) Metamorphic Rock Marble METAMORPHIC ROCK SEDIMENTARY ROCK IGNEOUS ROCK Metamorphic rock (marked altered rock) formed when the sedimentary rock surrounding the magma was softened (NOT MELTED) by the heat from the magma The melted rock becomes an igneous rock Metamorphic Rocks are classified as either foliated or nonfoliated FOLIATED •When the parent rock softens the mineral grains are flatten by heat and pressure •This causes the metamorphic rock to show a striped or banded look in some rocks •Examples of foliated metamorphic rocks are gneiss, schist and slate Granite f oliates i nto Gneis s parent rock foliated metamorphic rock Examples of foliated metamorphic rocks are Gneiss A beautiful specimen of foliation… gneiss Slate Schist Which sample shows foliation? #1 Which sample is showing finegrained igneous rock? #2 Which sample is showing a sedimentary rock? #4 NON-FOLIATED •Mineral grains grow and rearrange, but not form bands or stripes •Examples of nonfoliated metamorphic rocks include quartzite and marble Quartzite magnified quartzite no bands stripes FOLIATED OR NON-FOLIATED FOLIATED NON-FOLIATED FOLIATED NON-FOLIATED AMAZING EARTH SCIENCE FACTS Metamorphic rocks are formed by heat and pressure Metamorphic rocks include: (banded) Foliated • Examples are slate, schist and gneiss _(no stripes) Non-Foliated • Examples include marble and quartzite Parent Rock Metamorphic Rock Limestone morphs into Sandstone morphs into Shale morphs into _ _ marble _ quartzite _ and then into slate schist