Day 4

1. Day 4 What are the three major types of rock? igneous, metamorphic & sedimentary Based on the rock samples from the Compare Rock Types activity, what do most rocks appear to have in common? Most rocks are made of minerals. Daily Warm-Up Exercises 1

2. Compare Rock Formation, Part 1 Contrasting Case Activity 2 Earth History, Investigation 8 Compare Rock Formation

3. pumice granite Do you remember… ...how igneous rocks form? An igneous rock forms when molten rock cools and hardens. Igneous comes from the Latin word ignis, which means fire. Compare Rock Formation

4. Do you remember… schist quartzite ...how metamorphic rocks form? A metamorphic rock forms when an existing rock changes due to heat and/or pressure. Metamorphic means change in form. Compare Rock Formation 4

5. Cross Section of Earth Inner Core: solid 4700°C to 4800°C 3 to 4 million times SP Outer Core: liquid 3450°C to 4700°C 1 to 3 million times SP Mantle: upper (outer) part = rigid solid lower part = soft (plastic) solid 1200°C to 3450°C 32,000 to 1 million times SP Crust: rigid solid temperature can reach 1200°C pressure is up to 32,000 times surface pressure (SP)

6. Which is Which? – granite 11 Igneous Rock 1 – This rock is formed when molten rock cools and hardens. This process happens when magma pushes up into the crust but remains trapped underground. The temperature there is very warm, so the magma cools and hardens slowly. This slow cooling results in the formation of large crystals that are easily visible without a hand lens. This rock makes up a large portion of Earth’s crust and mountain ranges. Because it forms deep underground, it is not visible until the earth above it erodes or is dug up. This rock is rough and dull, but it has crystals that look smooth and shiny. It is also very hard and long-lasting, so it is often used for headstones and other monuments. Igneous Rock 2 – This rock is formed when molten rock cools and hardens. This process happens when a volcano erupts and molten rock cools quickly on Earth's surface. In fact, it cools so quickly that no crystals form at all. Instead, it forms a glass. This rock is smooth, shiny, and hard. Because it doesn’t have a crystal structure, it splits along smooth, curved edges. This feature makes it ideal for creating razor sharp tools. Such tools are often found during archeological digs, and some modern surgeons prefer blades made of this rock because they are sharper and thinner than steel. Look at rocks 11 & 16. Can you figure out which rock goes with which description? 16 – obsidian Do you remember what rock 11 is called?

7. Compare Igneous Cases case 1 = granite (11) Use this column for information that is true about one but not the other. Use this column for information that is true about both rocks. case 2 = obsidian (16) Fill in the table by entering information from the paragraphs to answer each question. Compare Rock Formation

8. Igneous Rock Formation hardens slowly because the molten rock is trapped underground, where it is very warm Molten rock cools and hardens. hardens quickly when a volcano erupts and molten rock cools on Earth's surface rough & dull, with large crystals that look smooth & shiny; very strong The rock is hard. no crystals; glass; smooth & shiny; splits along smooth, curved surfaces Compare Rock Formation

9. Which is Which? 20 – slate Metamorphic Rock 1 – This rock forms when shale, a sedimentary rock, changes due to heat and pressure. This process happens deep beneath Earth’s surface. Before the change, shale is a smooth, hard, dull rock with very fine grains arranged in layers. After the change, the new rock is also smooth with very fine grains, but it is harder, shinier, and more compact than shale. Shale often contains fossils, but the new rock rarely does. The biggest change is that the new rock can be easily split into sheets of different thicknesses. For this reason, it is often used to make roofing tiles and paving stones. Metamorphic Rock 2 – This rock forms when slate, a metamorphic rock, changes due to extreme heat. This process happens deep beneath Earth’s surface. Before the change, slate is smooth, fairly shiny, and hard. After the change, the new rock is rough and shiny, and small pieces tend to flake off easily. The biggest change is in grain size. Slate has very fine grains. The new rock has medium to coarse crystals that are flat and arranged in layers. Fossils are rarely found in slate or in the new rock. Look at rocks 1 & 20. Can you figure out which rock is which? 1 – schist Do you remember what rock 1 is called?

10. Compare Metamorphic Cases case 1 = slate (20) Use this column for information that is true about both rocks. Use this column for information that is true about one but not the other. case 2 = schist (1) Fill in the table by entering information from the paragraphs to answer each question. Compare Rock Formation

11. Metamorphic Rock Formation changes are caused by heat and pressure An existing rock changes due to heat and/or pressure. changes are caused by extreme heat new rock is harder, shinier, and more compact; easily splits into sheets of different thicknesses Fossils are usually destroyed. very fine grains become medium to coarse crystals that are flat and arranged in layers Compare Rock Formation

12. Compare Igneous & Metamorphic Look at your igneous table. Based on these two rocks, how do igneous rocks form? Igneous rocks form when molten rock cools and hardens. This process can happen slowly or quickly. Look at your metamorphic table. Based on these two rocks, how do metamorphic rocks form? Metamorphic rocks form when an existing rock changes due to heat and/or pressure. Compare Rock Formation

13. Compare Igneous & Metamorphic What properties result from igneous formation? Igneous rocks are usually hard. They usually have crystals, but obsidian does not have crystals. What properties result from metamorphic formation? Metamorphic rocks rarely have fossils because they are usually destroyed by the heat and/or pressure. Compare Rock Formation