Rocks, what do they mean to you? Some rock formations are famous and when they disappear, their legends don’tSome rock formations are famous and when they disappear, their legends don’t

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

Igneous Rocks Also known as “fire rocks”Also known as “fire rocks” They are formed by the crystallization of magma or lavaThey are formed by the crystallization of magma or lava Magma is the molten material found undergroundMagma is the molten material found underground Lava is the molten material found above groundLava is the molten material found above ground

Composition of Magma Magma is a slushy mix of molten rock, gases, and mineral crystalsMagma is a slushy mix of molten rock, gases, and mineral crystals It has the same major elements that are found in the earth’s crust: O 2, Si, Al, Fe, Mg, Ca, K, and NaIt has the same major elements that are found in the earth’s crust: O 2, Si, Al, Fe, Mg, Ca, K, and Na Magma is classified according to the amount of Si it containsMagma is classified according to the amount of Si it contains Rhyolitic (70%), Andesitic (60%), and Basaltic (50%)Rhyolitic (70%), Andesitic (60%), and Basaltic (50%)

Classification of Igneous Rocks Igneous rocks are classified according to their composition and textureIgneous rocks are classified according to their composition and texture Texture refers to the minerals of which rocks are formed, the shape, size, arrangement, and distribution of the mineralsTexture refers to the minerals of which rocks are formed, the shape, size, arrangement, and distribution of the minerals Ex: light colored rocks are rich in quartz, dark colored rocks might be rich in olivineEx: 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 - intrusive are coarse grained (large crystals) that cool slowly underground from plutons (granite) (granite)

Mineral Composition Felsic rocks are high in silicon and light colored. Ex: graniteFelsic rocks are high in silicon and light colored. Ex: granite Intermediate rocks have less silicon and are darker. Ex: DioriteIntermediate rocks have less silicon and are darker. Ex: Diorite

Mafic rocks are low in silicon and dark in color. Ex: gabbroMafic rocks are low in silicon and dark in color. Ex: gabbro Ultramafic rocks are very low in silicon and very dark in color. Ex: peridotite and duniteUltramafic rocks are very low in silicon and very dark in color. Ex: peridotite and dunite

Texture of Igneous Rocks Glassy igneous rocks look like glass and do not have their minerals arranged in crystalline formationGlassy 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 eyeAphanitic 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 seenPhaneritic 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 crystalsPorphyritic or mixed grained texture igneous rocks, large crystals embedded in a field of smaller crystals

Veins of Igneous Rocks Pegmatite contains very large grained minerals such as lithium and beryllium, as will as some of the most beautiful crystalsPegmatite 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 diamondsKimberlites are rare and can contain diamonds

And on we gooooooooo!

Sedimentary Rocks

Slowly Built Layers Sedimentary rocks are classified according to the origin of the material that they are made fromSedimentary rocks are classified according to the origin of the material that they are made from ClasticClastic OrganicOrganic ChemicalChemical

Clastic Clastic sedimentary rocks are made from the fragments of existing rocksClastic sedimentary rocks are made from the fragments of existing rocks They are further classified according to the size and shape of the fragments they are made ofThey are further classified according to the size and shape of the fragments they are made of

Conglomerates These are made from pebbles cemented together with mud, clay, or sandThese are made from pebbles cemented together with mud, clay, or sand Over one third is made of pebblesOver one third is made of pebbles

Sandstones Made from particles the size of sand At least half of the material must be sand to be classified as sandstone Grains are cemented together by minerals Most common sedimentary rock

Shales Made from particles smaller than sand Made from small particles of mud and clay Most can be split into flat pieces

Organic Rocks Organic sedimentary rocks are made either directly or indirectly from material that was once livingOrganic sedimentary rocks are made either directly or indirectly from material that was once living

Limestones May be produced by the shells of once living organismsMay be produced by the shells of once living organisms Living organisms may produce limestone directly as in coral reefsLiving organisms may produce limestone directly as in coral reefs

Chalk Fine grained limestone made from microscopic shellsFine grained limestone made from microscopic shells

Coal Formed from the remains of plants that lived millions of years agoFormed from the remains of plants that lived millions of years ago

Chemical Rocks Formed when a sea or lake dries up leaving behind large amounts of mineralsFormed when a sea or lake dries up leaving behind large amounts of minerals This includes rock salt, gypsum, and some limestoneThis includes rock salt, gypsum, and some limestone

The Making of Sedimentary Rocks Erosion and weathering of parent rockErosion and weathering of parent rock Transportation of sedimentsTransportation of sediments Deposition of sedimentsDeposition of sediments Compaction and cementation of sedimentsCompaction and cementation of sediments Lithification which turns the sediments into sedimentary rocksLithification which turns the sediments into sedimentary rocks

Interesting sedimentary rock structures

Had enough yet?

Metamorphic Rocks

Rocks that are caused by high pressure and/or heatRocks that are caused by high pressure and/or heat They are not completely meltedThey are not completely melted High temperature and pressure combine to change the texture, mineralogy, and chemical composition of igneous, sedimentary, and metamorphic rocksHigh temperature and pressure combine to change the texture, mineralogy, and chemical composition of igneous, sedimentary, and metamorphic rocks

Regional Metamorphic Rocks Large areas of metamorphismLarge areas of metamorphism

Contact Metamorphic Rocks Contact with an igneous intrusionContact with an igneous intrusion

Hydrothermal Metamorphism Contact with very hot waterContact with very hot water

Textures of Metamorphic Rocks Foliated have wavy layers and bands of mineralsFoliated have wavy layers and bands of minerals Non-foliated have minerals with blocky crystals shapes

Changes to Parent Rocks Mineral changes- one mineral changes to another due to the high heat and pressureMineral changes- one mineral changes to another due to the high heat and pressure Compositional changes- most of the composition of original rocks doesn’t change, hot liquid can alter the mineral and texture which can form valuable ore deposits like Au, Cu, Zn, W, and PbCompositional changes- most of the composition of original rocks doesn’t change, hot liquid can alter the mineral and texture which can form valuable ore deposits like Au, Cu, Zn, W, and Pb

GraniteGneiss LimestoneMarble Shale Slate SandstoneQuartzite BasaltSchist Shale Mica Schist

Rock Humor 1.What does a rock want to be when it gets older? 2.What do you call a dog who collects rocks? 3.What do you do to a baby rock? 4.What is a rock’s favorite kind of music? 5.Where do rocks sleep? 6.How do rocks wash their clothes? 7.What is a rock’s favorite transportation? 8.What is a rock’s favorite cereal?

Answers 1.A Rock star 2.A Rockhound 3.Rock it 4.Rock ‘n Roll 5.Bedrock 6.On the rock cycle 7.A rocket 8.Cocoa pebbles

The Grand Finale