Rocks, what do they mean to you? Some rock formations are famous and when they disappear, their legends dontSome rock formations are famous and when they.

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  • Rocks, what do they mean to you?Some rock formations are famous and when they disappear, their legends dont

  • Rocks The ones found in the Earth, not in some of your heads!!!!

  • Igneous RocksAlso known as fire rocksThey are formed by the crystallization of magma or lavaMagma is the molten material found undergroundLava is the molten material found above ground

  • Composition of MagmaMagma is a slushy mix of molten rock, gases, and mineral crystalsIt has the same major elements that are found in the earths crust: O2, Si, Al, Fe, Mg, Ca, K, and NaMagma is classified according to the amount of Si it containsRhyolitic (70%), Andesitic (60%), and Basaltic (50%)

  • Classification of Igneous RocksIgneous rocks are classified according to their composition and textureTexture refers to the minerals of which rocks are formed, the shape, size, arrangement, and distribution of the mineralsEx: light colored rocks are rich in quartz, dark colored rocks might be rich in olivine

  • There are two types of igneous rocks:extrusive are fine grained (small crystals) that cool on the surface of the Earth (obsidian, pumice, basalt)

  • - intrusive are coarse grained (large crystals) that cool slowly underground from plutons (granite)

  • Mineral CompositionFelsic rocks are high in silicon and light colored. Ex: granite

    Intermediate rocks have less silicon and are darker. Ex: Diorite

  • Mafic rocks are low in silicon and dark in color. Ex: gabbroUltramafic rocks are very low in silicon and very dark in color. Ex: peridotite and dunite

  • Texture of Igneous RocksGlassy igneous rocks look like glass and do not have their minerals arranged in crystalline formation

  • Aphanitic or fined grained igneous rocks have crystals present, but they are too small to be seen with the naked eye

  • Phaneritic or coarse grained igneous rocks have crystals that are about the same size and easily seen

  • Porphyritic or mixed grained texture igneous rocks, large crystals embedded in a field of smaller crystals

  • Veins of Igneous RocksPegmatite contains very large grained minerals such as lithium and beryllium, as will as some of the most beautiful crystals

    Kimberlites are rare and can contain diamonds

  • And on we gooooooooo!

  • Sedimentary Rocks

  • Slowly Built LayersSedimentary rocks are classified according to the origin of the material that they are made fromClasticOrganic Chemical

  • ClasticClastic sedimentary rocks are made from the fragments of existing rocksThey are further classified according to the size and shape of the fragments they are made of

  • ConglomeratesThese are made from pebbles cemented together with mud, clay, or sandOver one third is made of pebbles

  • SandstonesMade from particles the size of sandAt least half of the material must be sand to be classified as sandstoneGrains are cemented together by mineralsMost common sedimentary rock

  • ShalesMade from particles smaller than sandMade from small particles of mud and clayMost can be split into flat pieces

  • Organic RocksOrganic sedimentary rocks are made either directly or indirectly from material that was once living

  • LimestonesMay be produced by the shells of once living organismsLiving organisms may produce limestone directly as in coral reefs

  • ChalkFine grained limestone made from microscopic shells

  • CoalFormed from the remains of plants that lived millions of years ago

  • Chemical RocksFormed when a sea or lake dries up leaving behind large amounts of mineralsThis includes rock salt, gypsum, and some limestone

  • The Making of Sedimentary RocksErosion and weathering of parent rockTransportation of sedimentsDeposition of sedimentsCompaction and cementation of sedimentsLithification which turns the sediments into sedimentary rocks

  • Interesting sedimentary rock structures

  • Had enough yet?

  • Metamorphic Rocks

  • Metamorphic RocksRocks that are caused by high pressure and/or heatThey are not completely meltedHigh temperature and pressure combine to change the texture, mineralogy, and chemical composition of igneous, sedimentary, and metamorphic rocks

  • Regional Metamorphic RocksLarge areas of metamorphism

  • Contact Metamorphic RocksContact with an igneous intrusion

  • Hydrothermal MetamorphismContact with very hot water

  • Textures of Metamorphic RocksFoliated have wavy layers and bands of minerals

    Non-foliated have minerals with blocky crystals shapes

  • Changes to Parent RocksMineral changes- one mineral changes to another due to the high heat and pressure

    Compositional changes- most of the composition of original rocks doesnt change, hot liquid can alter the mineral and texture which can form valuable ore deposits like Au, Cu, Zn, W, and Pb

  • GraniteGneissLimestoneMarbleShale SlateSandstoneQuartziteBasaltSchistShale Mica Schist

  • Rock HumorWhat does a rock want to be when it gets older?What do you call a dog who collects rocks?What do you do to a baby rock?What is a rocks favorite kind of music?Where do rocks sleep?How do rocks wash their clothes?What is a rocks favorite transportation?What is a rocks favorite cereal?

  • Answers

    A Rock starA RockhoundRock itRock n RollBedrockOn the rock cycleA rocketCocoa pebbles

  • The Grand Finale

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