7th Grade Geology Lesson Tuesday, May 7th

Master the rock cycle! Explore igneous, sedimentary, and metamorphic rocks with this engaging 7th-grade geology worksheet.

Bill Nye - Rocks and Soil Watch the video before doing the reading and questions. Rock Cycle Diagram The Rock Cycle Reading The Rock Cycle is a group of changes. Igneous rock can change into sedimentary rock or into metamorphic rock. Sedimentary rock can change into metamorphic rock or into igneous rock. Metamorphic rock can change into igneous or sedimentary rock.Igneous rock forms when magma cools and makes crystals. Magma is a hot liquid made of melted minerals. The minerals can form crystals when they cool. Igneous rock can form underground, where the magma cools slowly. Or, igneous rock can form above ground, where the magma cools quickly.When it pours out on Earth's surface, magma is called lava. Yes, the same liquid rock matter that you see coming out of volcanoes.On Earth's surface, wind and water can break rock into pieces. They can also carry rock pieces to another place. Usually, the rock pieces, called sediments, drop from the wind or water to make a layer. The layer can be buried under other layers of sediments. After a long time the sediments can be cemented together to make sedimentary rock. In this way, igneous rock can become sedimentary rock.All rock can be heated. But where does the heat come from? Inside Earth there is heat from pressure (push your hands together very hard and feel the heat). There is heat from friction (rub your hands together and feel the heat). There is also heat from radioactive decay (the process that gives us nuclear power plants that make electricity).So, what does the heat do to the rock? It bakes the rock.Baked rock does not melt, but it does change. It forms crystals. If it has crystals already, it forms larger crystals. Because this rock changes, it is called metamorphic. Remember that a caterpillar changes to become a butterfly. That change is called metamorphosis. Metamorphosis can occur in rock when they are heated to 300 to 700 degrees Celsius.When Earth's tectonic plates move around, they produce heat. When they collide, they build mountains and metamorphose (met-ah-MORE-foes) the rock.The rock cycle continues. Mountains made of metamorphic rocks can be broken up and washed away by streams. New sediments from these mountains can make new sedimentary rock.The rock cycle never stops. 1. In paragraph #4, what does the word “sediments” mean? Read the passage above and answer the question. 2. In paragraph #4, what do you think the word “cemented” means? Read the passage above and answer the question. 3. Explain how sedimentary rocks are formed: Read the passage above and answer the question. 4. Which type of rock changes? Read the passage above and answer the question. Read the passage above and answer the question. 5. Igneous rock forms when magma (lava) cools off and forms crystals. 6. Where are 3 places that this passage says heat comes from in paragraph #5? Read the passage above and answer the question. 7. What is the most common type of rock found on the Earth’s crust? Read the passage above and answer the question. 8. What 2 types of rock are most common beneath the Earth’s crust? Read the passage above and answer the question. 9. Rock Type Table Complete the table. Rock Type How does it form? Picture Igneous Rocks Cooling of magma or lava Sedimentary Rocks Deposition of sediments and then compaction Metamorphic Rocks Heat and pressure changing the internal crystal structure of a rock 10. Rock Cycle Matching Match the type of rock with how it is formed: Igneous Forms when magma (lava) cools and makes crystals Sedimentary Forms when sediments become cemented together Metamorphic Changes by forming or making bigger crystals due to heat and pressure