1. Unit 2: Study Guide

2. What is a mineral? How are minerals formed?
A mineral is a naturally occurring usually inorganic solid that has a definite crystalline structure and chemical composition.
Minerals are formed:
As magma and lava cool
By metamorphism
From solutions

3. What is an element?
Elements are pure substances that cannot be broken down into simpler substances by ordinary chemical means

4. What is a compound?
A substance made up of atoms or ions of two or more different elements joined by chemical bonds.

5. What is the difference between silicate and nonsilicate minerals?
Silicate minerals contain silicon and oxygen, normally in the form of silicate tetrahedrons.
Nonsilicate minerals do not.

6. What are the different properties that can be used to identify minerals? Define each property.
Color- color of the mineral
Streak- color of the powdered form of the mineral. (Remember: that if a scientist draws on a white tile with the mineral, this is how the streak is found.)
Luster- way a surface reflects light
Cleavage and Fracture- The way the mineral breaks/splits
Density- measure of how much matter in a given amount of space.
Hardness- mineral’s resistance to being scratched.
Special Properties- any property specific to the mineral

7. Know the three different rock types: What are they
Know the three different rock types: What are they? How are they each created?
Igneous rock forms when magma or lava cools and hardens
Sedimentary rock forms from compressed or cemented layers of sediment.
Metamorphic rock forms from other rocks as a result of intense heat, pressure, or chemical processes.

8. What is weathering?
Weathering is the natural process by which atmospheric and environmental agents, such as wind, rain, and temperature changes, disintegrate and decompose rocks.

9. What is erosion?
Erosion is the process by which wind, water, ice, or gravity moves soil and sediment from one location to another.

10. What is deposition?
Deposition is the process in which material is laid down.

11. What is the rock cycle?
The rock cycle is the series of processes in which rock forms, changes from one type to another, is destroyed, and forms again by geologic processes.
Look in your book on page 78 for a diagram of the rock cycle.

12. What is uplift?
Uplift is the rising of regions of Earth’s crust to higher elevations.

13. What is subsidence?
Subsidence is the sinking of regions of the Earth’s crust to lower elevations.

14. What is a rift zone?
A rift zone is an area of deep cracks that forms between two tectonic plates that are pulling away from each other.

15. What are Earth’s compositional layers? (Make sure you can label them)
Crust
Mantle
Core

16. What is convection? Where does convection take place in Earth and why is it important?
Convection is the movement of matter due to differences in density that are caused by temperature variations; can result in a transfer of energy as heat.
Convection takes place in the Earth’s mantle.
Convection helps rocks move slowing in the mantle. (Cooler rocks sink and warmer rocks rise)

17. What are the Earth’s physical layers? (Make sure you can label them)
Lithosphere
Asthenosphere
Mesosphere
Outer Core
Inner Core

18. What is Pangaea? Why is the idea of Pangaea important in understanding Earth’s history?
Scientists think that about 245 million years ago the continents were joined in a single large landmass that they call Pangaea.
It’s important to understand that at one time scientists think that all the continents were connected and during millions of years the continents moved into their current locations.

19. What is sea-floor spreading?
Sea-floor spreading is the process by which new oceanic lithosphere sea floor forms when magma rises to Earth’s surface at mid-ocean ridges and solidifies, as older existing sea floor moves away from the ridge.
Older rock- far from ridge
Newer rock- formed near ridge

20. Theory of plate tectonics
This theory explains how large pieces of the lithosphere, called plates, move and change shape.

21. What is a tectonic plate?
A tectonic plate is a block of lithosphere that consists of the crust and the rigid, outermost part of the mantle.

22. Different plate boundaries (Know the arrow diagrams!)
Convergent- Two plates collide.
Divergent- Two plates move away from each other
Transform- Two plates move past each other horizontally

23. What are the three different mechanisms that cause tectonic plates to move?
Mantle Convection
Ridge Push
Slab Pull

24. What is an anticline? (Look on Page 107 for a diagram)
Anticlines- oldest layers of rock are in the middle of the fold. The youngest rocks are towards the outside.
Anticlines are shaped like a: n

25. What is a syncline? (Look on Page 107 for a diagram)
In syncline folds the youngest rocks are in the middle and the older rocks are on the outside edges.
Synclines are shaped like a: u

26. Faults Strike-Slip Faults Normal Faults Reverse Faults
Formed when rocks are under shear stress and at transform boundaries
Normal Faults
Formed when rocks undergo tension and at divergent boundaries
Reverse Faults
Formed when rocks undergo compression and at convergent boundaries

27. Faults
Be able to label a diagram of each fault, with where the hanging wall, footwall and fault plane are! (Look on page 109)

28. Three types of mountains
Folded Mountains- Form when rock layers are squeezed together and pushed upward.
Usually at convergent boundaries
Volcanic Mountains- Form when melted rock erupts onto Earth’s surface
Fault-Block Mountains- Form when tension makes the lithosphere break into many normal faults. Along the faults, pieces of the lithosphere drop down compared with other pieces. The pieces left standing form fault-block mountains.

29. What is an earthquake?
Earthquakes are ground movements that occur when blocks of rock in Earth move suddenly and release energy.
Label #6 page 116 in your book.
Know that the Focus is the point underneath the Earth
The Fault Line is the line between both of the plates
The Epicenter is on the Earth’s surface.

30. Label a volcano Label #5 on page 126 in your book. Know this!
Know magma is underneath the Earth & lava is when it has reached the Earth’s surface

31. Three types of volcanoes
Shield Volcanoes- Broad base, gently sloping sides, and form from mild eruptions.
Cinder Cones- Steep volcano formed from violent eruptions
Composite Volcanoes- Alternates between mild and violent eruptions.

32. Where do volcanoes occur?
Divergent boundaries
Convergent boundaries
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