6 th Grade Science Earth’s Processes

TCAP REVIEW 6th Grade Science Earth’s Processes

1. Minerals Minerals are inorganic, naturally occurring solids. A mineral is the purest form of itself. If I asked you all to bring carrots to class tomorrow, we would have a collection of carrots that may look a little different from each other, but basically they would all be carrots. Each mineral has only one “recipe”. Gold is just gold. It is ALWAYS Au. Minerals are like carrots because they are pure (not combined with anything else, only ONE recipe).

2. Rocks Rocks are a combination of two or more DIFFERENT minerals. If I asked you each to bring a salad to class tomorrow, we would have a collection of salads each with their own unique combination of ingredients. We would have taco salads, basic tossed salads, potato salads etc. Granite is a rock. There is no “recipe” for granite because it is composed of various and different amounts of minerals, mainly potassium feldspar, quartz, hornblende, and mica. Rocks are like salads because there are many recipes for each type of rock. They are a mixture of different minerals.

3. Quick! List the 3 types of rocks . . . • Igneous • Sedimentary • Metamorphic

4. Which rock type is most like a . . . Chocolate Fondue Hot Fudge English Toffee Sundae Explain why. Belgian Waffle

5. How do igneous rocks form? Forms when lava (on the Earth’s surface) or magma (inside the Earth’s crust) cools and then crystallizes.

6. How do sedimentary rocks form? 1. Small pieces of rocks are weatheredand eroded into sediments where they pile up. 2. Over time, these piles compact and are cemented togetherby minerals in water.

7. How do metamorphic rocksform? Heat and pressure from inside the Earth change old rocks into new rocks (recycled rocks)!

8. Rock Cycle Rocks constantly weather and erode, get pushed down into the Earth and sometimes even melt. They travel through the rock cycle. On your own paper, fill in the arrows with each process (use the word bank) to show how rocks move through the rock cycle.

9. Which rocks might contain fossils? ONLY sedimentary rocks will contain fossils… because fossils would be melted in igneous rocks and crushed or melted in metamorphic rocks. • 10. How do fossils form? • Critter dies and is quickly covered • and protected by sediments • Soft tissues decay while bones and • teeth remain • 3. Minerals eventually replace (fossilize) • the hard material • 4. Fossil is uplifted through weathering • and erosion and becomes visible at the surface

11. How does ROCK become SOIL? • First . . . • Bedrock (big solid rock) is weathered into smaller sediments. • These sediments are eroded and deposited in new areas. • Mosses start to grow in the new sediments. Their roots help to further break down rocks.

11. (continued) • Next . . . • Grasses and shrubs begin to grow. • Their roots continue to break apart the larger sediments. • Organic matter builds up as plant matter dies and decomposes into the soil.

Finally . . . • Larger trees grow. Roots break apart and aerate the soil. Leaves add organic matter. Leaf Litter • Earthworms aerate the soil. Topsoil • Small animals loosen soil and add organic matter. Subsoil Bacteria and fungi decompose the organic matter making it easier for plants to absorb. Parent Material

12. What can paleontologists learn from studying fossils and the rock layers we find them in? • We can figure out what past environments were like • We can learn about what past organisms were likeand when they went extinct • We can look at how climates have changed • We can learn how old fossils are depending on where we find them in rock layers

Squid butts in Wyoming?

13. Principle of Superposition The youngest layer is on the top and the oldest on bottom, each layer being younger than the one beneath it and older than the one above it.

14. Sometimes the sequence of layers can change due to uplift, breaking, faults and foldingfrom plate movement. We can still use clues in rocks and index fossils to put the puzzle together.

15. Earth is cracked up! The Earth’s crust is cracked into plates. The theory that explains how these plates move is called plate tectonics.

Notice the yellow lines on this map. These are plate boundaries. Depending on which direction the plates move, different geologic events can take place.

When plates move away each other… (Divergent Boundary) (oceanic plate – oceanic plate)

16. What happens at a divergent boundary? Mid-ocean ridges Seafloor Spreading (oceanic – oceanic)

Mid-Atlantic Ridge

When plates move toward each other…(Convergent Boundary) (oceanic – continental) (continental – continental Plates Coming Together (one plate subducts beneath the other)

17. What happens at a convergent boundary? Volcano Trench (oceanic – continental) Subduction Earthquakes

Marianas Trench

18. What else happens at a convergent boundary with land on top of each plate?? mountain formation (continental – continental)

19. The most common type of mountains are folded mountains. The Rocky Mountains are an example of folded mountains. As the plates move towards each other, the land on top of the plates folds on top.

How did the Himalayan Mountains form?

19. Mt. Everest is also an example of folded mountains.

When two plates slide past each other in opposite directions…(TransformBoundary) (continental – continental)

20. What happens at a transform boundary? Faulting Earthquakes (continental – continental))

21. The San Andreas Fault is a crack in the Pacific plate that runs along the coast of California causing many earthquakes in that area.

Weathering and erosion-wearing down and building up Our constantly changing Earth! PLATES ON THE MOVE—earthquakes, volcanoes, trenches, mountain formation, ocean ridges, seafloor spreading, faults Rock recycling and recycling and recycling…

6 th Grade Science Earth’s Processes