Weathering

Question 1

4 stages of landscape development

Answer 1

• youth
• maturity
• old age
• rejuvenation

Question 2

Describe the youth development stage

Answer 2

Dominant forces present that uplift the crust (earthquakes, etc.)
Folds and faults form high mountains - steep slopes. Streams are in V-shaped valleys.
E.g. Rocky Mountains

Question 3

Describe the maturity development stage

Answer 3

Erosion forces cause leveling, lower altitude mountains, less rugged. Streams in narrow flat-bottomed valleys (like the App. mountains)

Question 4

Describe the old age development stage

Answer 4

Landscape pretty flat, erosion forces smaller part. Streams and rivers meander (like Nile and Mississippi)

Question 5

Describe the rejuvenation development stage

Answer 5

Uplifting forces dominate again. Streams now elevated and cut new valleys and steeper slopes

Question 6

Two basic types rock weathering

Answer 6

mechanical

chemical

Question 7

Mechanical weathering

Answer 7

Breakdown of rock by physical means: frost, temp changes, planet growth, condensation, animal/human activity

Question 8

How do lichens, water, oxygen, and carbon dioxide chemically weather rock?

Answer 8

Lichens - release mineral-dissolving acids
Water - combines chemically to convert minerals to weaker minerals
Oxygen - combines with substances (oxidation); some rocks rust
Carbon dioxide - forms carbonic acid with water, which then dissolves limestone to form underground caverns

Question 9

Chemical weathering

Answer 9

breakdown of rock by chem. reaction with substances like acids, water, oxygen, CO2

Question 10

2 factors for weather-resistence

Answer 10

Mineral composition - rocks that are mostly quartz are most resistent while feldspar and sedimentary rock weather readily
The more rainfall, the faster rock weathers

Question 11

Humus

Answer 11

Decayed plant and animal remains; a primary part of soil

Question 12

5 primary components of soil

Answer 12

humus
bacteria
sand
minerals
clay

Question 13

3 common types soil

Answer 13

sandy - doesn’t hold much water; grainy; binds poorly
clay - smooth; binds well; water doesn’t pass easily
loam - clumpy; mixture of sand, silt, clay; good for growing plants

Question 14

Topsoil

Answer 14

Top layer of soil where plants grow; not more than 24 inches deep; contains humus; is often loam

Question 15

Groundwater

Answer 15

Water underground. Water is found anywhere below the surface of the Earth. The depth varies from a few inches to several thousand feet.