Rocks

Three Types of rock Igneous Metamorphic Sedimentary Three totally different types of rock that all basically come from the same materials

Q: So how do we get such different rocks? Igneous Rocks? Metamorphic Rocks? Sedimentary Rocks? They all look and act so differently, how do they all form?

A: The Rock Cycle!!! Metamorphic Rocks Igneous Rocks Sedimentary Rocks can become Main Concept: Any rock type can be changed into any of the other two and back again through the Rock Cycle depending on conditions The process of rocks changing from one type of rock to another

Molten material comes from volcanoes Igneous Rocks The type of igneous rock depends on how fast it cooled! All Igneous rock comes from molten material

How to get Igneous Rocks: Melting of Material Cooling Magma Explosive Volcanism Can you see the big differences in these two rocks? Large CrystalsLots of holes Is made from cooled magma down here Is made from exploding material up here

Weathering If rocks are exposed at the surface; they are exposed to the elements in the air. All the “elements”: rain, wind, animals, plants, ice and even simply a release of pressure can cause the chemical bonds in rocks to break apart. The process of breaking the bonds in rock and making it “softer” is called: Weathering!

Erosion After a rock has been weathered, it is easy to break. If a rock breaks into pieces it becomes easier to move from one place to another. The movement of rock pieces and or soil from one place to another by natural processes is called: Erosion! The cliff is slowly falling down! The pile of sediments here used to be part of this cliff!

Sedimentary Rock =cemented sediments The sand here is loose and not cemented together This Sandstone in Utah is made from sand that has been cemented together Can you see the different layers of sand?

Sedimentary Rock Recipe 1. Start at the Surface 4. Sedimentation & Deposition 5. Compaction & Cementation 2. Weather (Break Up) 3. Erode (Carry Away) © Beadle, 2009 Sediments worn away gather here! Igneous rock Layers of sand and sediments Rain moves sand, dirt, and rocks down to the ocean

How to get Sedimentary Rocks: Erosion Weathering DepositionCementation Water and pressure helps bond the particles of sediment together to make a rock Rocks get broken down by exposure to water, wind, etc… Broken down sediments are transported towards the sea and spread out Broken down rocks fall apart

Weathering (Rock broken down by exposure to rain, wind, etc..) Erosion (pieces fall down to bottom of cliff) Deposition (smaller pieces are spread out across area) Cementation (eventually pieces get stuck together and becomes a rock) This is what it looks like in real life:

Rivers can do a lot of this on their own: Deposition is taking place when the river meets the ocean You can see lots of sediments flowing in the river You can see lots of sediments spreading out!

Now all that is left are salty rocks that form a dry lake bed Evaporation: New rocks can be formed when water is evaporated There used to be a nice deep ocean here But then the water evaporated… When the water leaves, the electrons of the chemicals that make up the rocks are attracted to each other and cause clumps of rock to form from the small particles left behind.

Limestone is very common in the mountains of Utah Q: Where did this limestone originally come from? A: Underwater! Limestone is the remains of sea critters shells that have been compacted together to form rock at the bottom of a sea

Pressure and Heat Lead to Metamorphic Rocks Rocks that get buried again can get squished and heated to the point that they change! This rock is called “Gneiss” (nice). Q: Can you remember what it has “morphed” from? A: Granite!!! If you look closely, you can see the same minerals in both rocks!

The white tops of these mtn’s are granite= Igneous Erosion is actively breaking down the mountains (forming canyons!) Deposition: minerals from the Granite spreading out as sand! (This makes the soil of the valley) The rock cycle is an active process that you can see just about everywhere outside: Underneath all the sand, sediment is being compacted =Sedimentary Soil is basically all the small broken up pieces of rocks! Broken down tons of times into smaller and smaller sediments

***You will need to know the process to make each type of rock! The Real Rock Cycle

Rock Cycle with illustrations:

Hot Mantle Cooler Crust Plate motion Convection current Q: What rock will we get if two continental plates collide? Let’s connect the rock cycle with plate tectonics!

Hot Magma Compression = Metamorphic Plate motion Continental plate collides with Continental Plate causing mountains to form!

Cloud will bring falling water Label where metamorphic, igneous & sedimentary rocks are formed as the numbers appear: Hot Mantle plate motion 2 Earthquakes 4 Volcanic Explosion Extrusive Igneous Rock Continental collides with Oceanic: Divergent Convergent 3

Plate Tectonics Rock Cycle Key: Notice where metamorphic, igneous & sedimentary rocks are processed & formed. Cloud Sedimentary Extrusive Igneous Intrusive Igneous Metamorphic Intrusive Igneous Metamorphic Melted rock Extrusive Igneous

Identify where the terms/description on the left should go in the rock cycle on the right Assessment: Identify where the terms/description on the left should go in the rock cycle on the right Heat, Pressure Extrusive (Volcanic Eruptions) Deposition & Cementation Melting Intrusive (Cooling & Crystallization) Weathering & Erosion

The Rock Recipes make the Rock Cycle: Igneous Rock Take minerals & Add a lot of Heat to Melt Cool & Crystallize (Extrusive) Change to Liquid Phase (Magma) Rise to the Surface Sedimentation & Deposition Compaction & Cementation Weather (Break Up) Erode (Carry Away) Sedimentary Rock Cool & Crystallize (Intrusive) burry it deep underground Add Heat & Pressure (Not too hot) Cool & (Re)-Crystallize Metamorphic Rock

a 7 The Rock Cycle for real: 6b What Rock? What Rock?