Download Review Questions For Earth crust (answers)

Review Questions For Earth’s Crust Unit
1. List the 4 layers of the earth starting from the surface to the center.
Crust, Mantle, Outer Core, Inner Core
2. What is the main composition (what it is made of) of each of the layers?
Crust- Rocks and minerals
Mantle- Molten magma/Molten Rock
Outer core- Liquid Iron and liquid Nickel
Inner Core- Solid Iron and Nickel
3. Which layer is the hottest and which layer is the coldest?
The hottest is the Inner Core and the coldest is the Crust.
4. What theory did Alfred Wegner discover? When was his discovery recognised in
the scientific world?
Alfred Wegner discovered the Theory of Continental Drift. The discovery was only
recognized in the scientific world many years after his death; most scientists thought
his theory was ridiculous during his lifetime.
5. List three observations that Alfred Wegner made to come to this conclusion?
1) The coastline appear to fit together
2) Fossils of tropical trees and animals have been found in Antarctica
3) Rocks from the Eastern coast of North America are the same type and
age as the rocks on the coast of Europe
6. What was the name of the supercontinent Wegner described?
Pangaea
7. Explain how the Atlantic Ocean is becoming 3 cm wider each year.
There is a place in the Atlantic Ocean where two Giant Plates meet. This plate
boundary is called the Mid Atlantic Ridge and is where the two plates separate from
each other. Magma from the Mantle rises up between the two plates and slowly
wedges the two plates apart which eventually widen the Ocean.
8. What are the giant sections are of rock floating on the earth’s interior called?
Plates
9. Find the definition to the following terms: Subduction, Fault, Separation as they
apply to the earth’s crust.
Subduction- the collision between two of the planet's tectonic plates, the pieces of
crust that slowly move across the surface over millions of years. When two tectonic
plates meet, one may slide underneath the other, curving down into the mantle.
Seperation-When the Magma rises from the mantle to push two plates apart
Fault- An area where two plates move parallel to each other and rocks are broken
by the movement.
10. Using the terms from question 9, where do earthquakes and volcanoes form and
why do they form?
Earthquakes often form where plates collide and where there are subduction zones.
The frictions from the plates rubbing together cause earthquakes. The same thing
can happen at fault zones where plates slide parallel to each other.
Volcanoes happen when magma from the mantle rises from the surface and creates
volcanoes. This can happen at subduction zones aswell.
11. What is the name for the volcanoes and earthquakes that surround the Pacific
Ocean?
Pacific Ring of Fire
12. List the three types of rocks and explain how do they form?
Igneous Rock- Formed when hot magma from the Mantle cools down quickly.
Sedimentary Rock- Formed after layers of sediment accumulate at the bottom of the
ocean and turns to rock over millions of years
Metamorphic Rock- Changes already formed rock into new rock under great heat
and pressure.
13. List 5 different tests you can do to classify different minerals and rocks.
Hardness, Color, Lustre, Streak, Rupture, Cleavage, Form, Transparency
14. Describe the difference between weathering and erosion.
Weathering- is the action of natural processes breaking rocks into smaller pieces
Erosion- the process of sediment or small pieces of rock moved from one place to
another.
15. List the three types of weathering, and give and example for each one.
Mechanical Weathering – the physical action of breaking rock into smaller pieces
Examples- Ice forming in cracks of rocks, Animals walking on the rocks, sun on
rocks
Chemical Weathering- Breaking rocks apart using chemical reactions
Examples – Acid rain helps weaken certain types of rocks, Metals dissolve from
rocks from the rain
Biological Weathering- Living things breaking rocks apart
Example : tree roots, lichens dissolving the rock
16. List three types of Erosion and explain why it is a cause of erosion?
Wind, rain, rivers
Wind moves the sediment and small particles from one spot to another
River moves large amounts of rock and sediment down the river
Rain can cause rocks and sediment to move down a mountain or hill