The Rock Cycle

How can this be a cycle? What rock forms when magma cools? –igneous rock How is sedimentary rock formed? –pressure and cementing of sediment What happens to rock when it melts? –It’s magma

What are igneous rocks? Rocks formed from magma that’s cooled.

How are granite and basalt related? Continental crust = mostly granite (large crystals formed underground).  Oceanic crust = mostly basalt  (small crystals formed at the surface). They are both igneous rocks !

Where do sedimentary rocks come from? They’re formed by layers (sediments) that are the pieces of other rocks, that are (stuck or glued) cemented by minerals that were left behind by water (deposited). 

How are sand, sandstone, and conglomerate connected? Sand comes from weathering & erosion. Wind, water, or ice cause pieces of rock to break off of larger rocks…

…sandstone and conglomerates; they’re all sedimentary rocks that were cemented together with the pieces of other rocks.

What are metamorphic rocks? Rocks formed when existing rocks are changed by heat and pressure. Heat and Pressure Sedimentary (limestone) Metamorphic (marble)

How are shale and slate connected? The sedimentary rock, shale is changed into the metamorphic rock, slate by heat and pressure. shale slate

What are the 3 classes of rock? Petrologists classify rocks by how they form. 2. ___________ - pieces of minerals, rock, and living things that compacted together 1. ________ - melted rocks (minerals) that have cooled 3. __________ - any rock that is changed by heat and pressure (not fully melted) Igneous Sedimentary Metamorphic

The Rock Cycle

1. Rocks are minerals cemented together 2. There are three classes of rock: Igneous: formed from cooling magma Metamorphic: igneous, sedimentary, or metamorphic rock changed by heat/pressure Sedimentary: formed from sand (broken down rock) cemented together. 3. As you go deeper in the Earth, the temperature increases or gets hotter. Concept and Challenges – What are rocks? 4. Igneous rocks are made from magma. As magma cools it forms igneous rocks.

5. The three main minerals that make up granite are quartz, feldspar, and mica 6. Obsidian does not have crystals because it is lava that cooled too quickly 7. Sediments are small parts of rock that are carried and deposited by water, wind, or ice 8. Acid reacts with calcium, and because the sedimentary rocks from the White Cliffs of Dover have calcium carbonate (CaCO 3 ), the acid would react.

9. Clastic rocks are made up of smaller rocks that are nonliving, but nonclastic rocks are made up of dissolved minerals or dead plants and animals. 10. Metamorphic rocks are formed by rocks that are changed by heat and pressure. 11. You can make bread from water, flour, salt, and yeast. First, you mix the ingredients. Then, you bake the mixture in an oven. 12. The minerals in the rocks melt and recrystallize into minerals that form bands.

The Rock Cycle Do you know… 1.What is the connection between shale and slate? 2. What is the connection between granite and basalt? 3. What is the connection between obsidian and pumice? 4. What is the connection between sand, sandstone and conglomerate?

Shale and Slate The sedimentary rock shale is changed into the metamorphic rock slate by heat and pressure. Granite and Basalt They are both igneous rocks. Granite makes up most of the continental crust and basalt makes up oceanic crust. Obsidian and Pumice They are both igneous rocks formed by the quick cooling of lava. Obsidian is from lava that flowed and pumice was violently ejected from a volcano. Sand, Sandstone and Conglomerate The sand is sediment that has formed into the sedimentary rocks sandstone and conglomerate.