ch. 8 test

Question 1

Structure of Earth

Answer 1

Crust
Lithosphere
Asthenosphere
Mantle
Outer Core
Inner core

Question 2

why is earth hot

Answer 2

• remnant heat from formation
• pressure from gravity
• decay of radioactive isotopes

Question 3

Oceanic Crust

Answer 3

• made of basalt
  -greater density than granite

Question 4

Continental Crust

Answer 4

• made of granite

Question 5

Examples of Convergent Boundaries

Answer 5

• Cont-Cont
  -Ocean-Cont
  -Ocean-Ocean

Question 6

Cont-Cont

Answer 6

-Collision boundary
-Mountains get pushed up
Earthquakes, Landslides, Avalanches
-Ex. India into China

Question 7

Ocean-Cont

Answer 7

-Ocean plate subducts under the continent
-plate melts under the continent, forms volcanoes
- trench forms at the boundary
- earthquakes
-Ex: Andes Mountains, Cascade Mountains

Question 8

Ocean-Ocean

Answer 8

-One plate subducts under the other
- melts and forms island arc of volcanoes
-volcanoes, earthquakes, deep sea trenches
- Aleutian Islands, Japan, Philippines

Question 9

Subsurface mines

Answer 9

• Coal and rich metals
• Hazards: Mine collapse, Dust+debris, methane
  -acid mine drainage- sulfuric acid into water

Question 10

Placer mine

Answer 10

• hydraulic mining of stream gravels (gold)
• destroys habitat

Question 11

open pit mine

Answer 11

• quarry
  -small open pit used for stone gravel and sand

Question 12

strip mine

Answer 12

remove soil+rock, mine coal, replace soil+rock
-go strip by strip
-Ex: Montana/Wyoming coal mines

Question 13

Mountain top removal

Answer 13

• commonly done in WV
  -remove top of mountain then mine what’s below

Question 14

igneous rocks

Answer 14

• formed from the cooling and crystallization of magma/lava
• Ex. Basalt, granite

Question 15

sedimentary rocks

Answer 15

-rocks made of sediments
- sediment: broken down pieces of rock
- Sand, silt, clay
-pressed+glued together
-Ex. sandstone, limestone, shale

Question 16

metamorphic rocks

Answer 16

• rocks that are chemically or physically altered by heat or pressure
• sandstone to quartzite
• limestone to marble
  -shale to slate
  -granite to schist/gneiss

Question 17

physical weathering

Answer 17

-ice water wedging
-tree roots cracking rocks
- thermal expansion+contraction

Question 18

chemical weathering

Answer 18

-mineral oxidation
-dissolving of minerals by acid rain
-salt corrosion
-plant secretion

Question 19

erosive agents

Answer 19

water
wind
glaciers

Question 20

Why are soils important

Answer 20

foundation for terrestrial ecosystems
90% of the world’s food
easily erodible, not quickly replaced

Question 21

3 components of soil

Answer 21

-detritus
-inorganic mineral matter (sand/silt/clay)
-Critters (Fungi bacteria insects)

Question 22

soil texture

Answer 22

% composition of sand, silt and clay in a given soil

Question 23

Soil horizons (in order)

Answer 23

O horizon
A horizon
E horizon
B horizon
C horizon
Ohern asks everyone bring cookies

Question 24

O horizon

Answer 24

• detritus/organic matter
  -nutrients/food for critters
  -retains moisture
  -reduces erosion

Question 25

A horizon

Answer 25

-topsoil (sand silt clay humus)
- home of critters
- where roots live and get nutrients

Question 26

E horizon

Answer 26

eluviation- zone of leeching
- mineral nutrients deposited down

Question 27

B horizon

Answer 27

• deposition of minerals/nutrients in clay form
  -subsoil

Question 28

C horizon

Answer 28

• weathered parent material
  -bedrock

Question 29

what do plants get from soils?

Answer 29

-mineral nutrients
-gas exchange
- water
-proper pH

Question 30

organic fertilizers

Answer 30

-composted leaves/manure/plant remains
-adds detritus/humus to promote soil health

Question 31

inorganic fertilizers

Answer 31

• add NH4+ or NO3- or PO43-
  -can be unhealthy