Exam Review

Question 1

What were the 4 basic forces that separated out during the Big Bang?

Answer 1

1. Gravity (attraction of bodies)
2. Electromagnetic force (electricity & magnetism)
3. Strong Magnetic Force (hold neutrons and protons together)
4. Weak magnetic force (breakdown of atoms=radioactive decay)

Question 2

What are the 5 characteristics of a mineral?

Answer 2

1. Naturally occurring
2. Inorganic (not living)
3. Crystalline solid
4. Defined chemical composition
5. Characteristic physical properties

Question 3

4 types of Bonds?

Answer 3

1. Ionic: chemical bonding attraction between 2 ions of opposite charge
2. Covalent: the sharing of e- between atoms
3. Metallic: extreme e- sharing. E- of the outer most electron shell easily move from one atom to another
4. Van der Waals: (residual bond) Weak attractive force when no e- are available

Question 4

What limits the amounts of minerals (3,500) that exist?

Answer 4

Many combinations of elements simply don’t occur. Bulk of earths crust is made up of only 8 chemical elements

Question 5

Difference between ferromagnesian and non-ferromagnesian silicate minerals?

Answer 5

Ferromagnesian contains iron, magnesium or both and is usually darker and dense. Non-ferromagnesian does not contain iron or magnesium and is light colored and less dense.

Question 6

2 major ways minerals form

Answer 6

Form out of a solution. Crystallization of magma or lava

Question 7

2 sources for magma

Answer 7

Crust: more silica rich.

Upper mantle: less silica, more ferromagnesian silicates

Question 8

How are magmas classified?

Answer 8

Magmas are classified according to how much Si they contain

Question 9

Viscosity:

Answer 9

A liquids resistance to flow

Question 10

High viscosity:

Answer 10

all natural peanut butter (flows slow/not very easily)

Question 11

Low viscosity:

Answer 11

honey (flows faster/smoother)

Question 12

What changes the composition of magma?

Answer 12

Crystal settling: physical separation of minerals by crystallization and settling.
Assimilation: magma reacts with country rock

Question 13

What are Plutons?

Answer 13

An intrusive igneous body that forms when magma cools and crystallizes within the crust.

Question 14

Volcanism:

Answer 14

Process by which magma rises and issues onto Earth’s crust.

Question 15

What are the names of the two common lava flows? What’s the difference between the 2

Answer 15

Pahoehoe: Ropy surface like taffy, less viscous
Aa: Jagged and angular, more vicsous

Question 16

Volcanoes:

Answer 16

Classified by eruption characteristics as either quiet vs. explosive.

Question 17

Quiet Volcanoes

Answer 17

Low silica percentage = mafic rocks = flow faster = smoothers, more fluid and not as eruptive

Question 18

Explosive Volcanoes:

Answer 18

High silica percentage = felsic rocks = flow very slow, eruptive, thick

Question 19

What are the two types of sediment?

Answer 19

Detrital: solid particles from preexisting rocks
Chemical: minerals that precipitate from solutions and minerals derived from water by organisms to build shells (biochemical sediments)

Question 20

What are the 5 types of weathering?

Answer 20

1. Frost Actions
2. Pressure Release
3. Thermal Expansion/Contraction
4. Salt Crystal Growth
5. Living Organisms.

Question 21

3 types of metamorphism and how they differ?

Answer 21

1. Contact (thermal) metamorphism
2. Dynamic metamorphism
3. Regional metamorphism

Question 22

Agents of Metamorphism?

Answer 22

1. Heat: Increases rates of chemical reactions
2. Pressure: Pressure increases with depth
3. Fluid activity: Water (and carbon dioxide) are present in almost every region of metamorphism

Question 23

What does metamorphic grade mean?

Answer 23

the degree to which a rock has undergone metamorphic change

Question 24

Foliated texture

Answer 24

Platy and elongate minerals aligned in a parallel fashion

Question 25

Nonfoliated texture:

Answer 25

no discernable preferred orientation of minerals. Contact or regional metamorphism of rocks with no platy or elongate minerals

Question 26

Metamorphism

Answer 26

the phenomenon of changing rocks subjected to heat, pressure, and fluids so that they are in equilibrium with a new set of environmental conditions

Question 27

What is Parent material

Answer 27

rocks acted on by weathering

Question 28

What is Weathering?

Answer 28

the physical breakdown and chemical alteration of rocks and minerals at or near the Earth’s surface

Question 29

Chemical weathering

Answer 29

decomposition of rocks by chemical alteration of parent material (plants, algae, acid rain)

Question 30

How are detrital sedimentary rocks classified?

Answer 30

Classified by size of particles

Question 31

What are the soil formation factors and which is most important?

Answer 31

Climate most important
Temperature
Precipitation
Varies by latitude, affects vegetation • Rock type can have some control

Question 32

What is soil? What does it consist of (it’s composition)?

Answer 32

• Humus: microorganisms decompose leaf and grass litter – Release nutrients into soil
• Burrowing animals mix soils and create channels for air and water

Question 33

Ways in which soil is degraded?

Answer 33

• Any process that leads to loss of soil productivity
• Erosion: natural process that humans accelerate (plowing, overgrazing, deforestation)
• Erosion from running water:
• Nutrient depletion from intensive agriculture • Salinization: increased salts in soil
• Contamination with toxic substances
• Compacted soils

Question 34

Mechanical Weathering?

Answer 34

• disaggregation of rocks by physical processes that creates smaller pieces that retain parent composition