Geologists classify rocks into three majorgroups depending on how they are formed: Igneous rock, Sedimentary rock, and Metamorphic rock.
• Formed from cooled Lava and MagmaAs an Example: Liquid hot lava can become ***When the lava cools and turns into a solid, it can turn into quartz!
- Igneous Rocks1. Take some Minerals & Gasses – Mix well2. Add Heat Energy & Melt (cook for +/-10 thousand years) 3. Turn to Magma (Liquid Molten Rock) 4. Cool & Crystallize (Intrusive/Extrusive) Minerals + Heat 5. Igneous Rock under the Serve and Enjoy ground
• Formed inside the crust/mantle.• These types always have large visible crystals. (cooled slowly)• Ex: Granite and Gabbro This is a special kind of Granite ***Notice that both rocks have called: “Pink Granite” easy to see crystals
• When magma from below rises up, but does not make it to the surface, the minerals start to crystallize slowly and form large crystals. Notice the bulge that forms! = there might be an eruption soon! Or not… This became Granite Magma because it never made it to the surface!
• Formed on top of the crust.• Small, hard to see crystals (cooled quickly)• Ex: Pumice, Obsidian ***No visible crystals in either rock
• When magma from below rises and Blam! punches through, the minerals don’t have time to crystallizeash, gasses, they – therefore, volcanic glass, etc. Other types of produce rocks with small crystals. rock can be blasted out Lava Flow (Outside) The lava will quickly Magma cool into solid rock! (inside)
• Granite and Rhyolite: can you see crystals? Rhyolite form from the same type of cooled magma.• If the magma cools rapidly, smaller There are no visible crystals! crystals form and Rhyolite rock is Granite: can you see crystals? produced.• If the magma cools slowly, larger There are lots of visible crystals! mineral crystals form and the type of rock
• Formed by sediments (pieces of rock, shells, and dead organisms) becoming “cemented” (stuck) together. Sandstone Coal Limestone Conglomerate***You can see lots of different stuffstuck together in these rocks!
1. Rocks exposed at Rise to the the surface Surface Weathering2. Weather (Break Up) & Erosion Sedimentation & Deposition3. Erode (Carry Away) Compaction 4. Sedimentation & Deposition Cementation (stuck together) 5. Compaction & Cementation ***Notice that different layers of “sediments” are forming
• Made from other rocks Take notice of small pieces of rock stuck together
• Made from parts of living things. Notice all the shells stuck together
• Formed through evaporation.• (ex: limestone) All this Limestone used to be on the bottom of an ocean! (ocean floor) ***Limestone is made up of the Calcium (shells) and Carbon (bodies) from once living things (dead)In fact, we call Limestone: in the water (oceans). Calcium Carbonate!
• Particles of shells/rocks stuck together• Dull (not shiny)• Straight layers Sandstone: pieces of sand stuck together• Fossils (often) The layers are going in this direction can you see them?
• To “Morph” means to •change it!have changed. Rocks that “…more than meets the eye!” • They were once Igneous or Sedimentary rocks that got buried DEEP under ground. • The heat and pressure from being deep underground changed the rocks. • Has large, inter-grown crystals in thin “bands” (Foliated) or clusters (Non-Foliated).
1. Get some pre-formed rock –Igneous or Sedimentary will do.2a. Add Heat 2b. Squeeze “cook it” (pressure) to “Foliate” 3. Cool & (Re)-Crystallize Heat and pressure 4. Metamorphic Rock!!! Note: If it meltscompletely and cools; It will turn back into an Rocks are Igneous Rock “Morphed”
• Mineral crystals aligned in parallel layers. Notice that the crystals have been squished into mostly straight lines.
The shoes represent the pressure caused by all the rock above the crystals The “playing cards” represent mineral crystals in a rock! Crystals are large Crystals have become “squished”
Crystals Crystals are line up in Random in mostlytheir locations straight linesHE AT e sur P res Granite=large, randomly Gneiss=smaller, lined located crystals becomes up crystals
• Gneiss:• Schist: Can you see all the Straight layers of crystals?• Slate: