1. What are the two types of weathering? Define both.
The two types of weathering are mechanical and chemical. Mechanical weathering is the process by which
rocks are broken down physically. Chemical weathering is the process by which rocks break down
chemically.
2. What are the agents of mechanical and chemical weathering?
The agents of mechanical weathering are water, wind, abrasion, and living things such as plants and
animals. The agents of chemical agents are acid precipitation, acid in ground water, oxidation, and
acids in living things such as bacteria, lichen, fungi, and algae. [Water, oxygen, carbon dioxide, and acids]
3. How does ice wedging (frost action) break down rock?
Waters seeps into cracks of rock during warm weather, freezes and expands during cold weather, and
continues the cycle.
4. Explain how lichens break down rock.
Lichens attach to rocks. Weak acids produced by the plant begin to weaken the rock. As the rock is exposed
to the weak acid, the rock weathers over time.
5. How do acids in ground water cause caves to form?
Weak acids (carbonic or sulfuric acids) in groundwater react with rocks (limestone) in the ground causing a
chemical reaction to occur. Over a long period of time, the dissolving of the rock forms karst features such
as caverns.
6. What is oxidation? Where does oxidation occur?
Oxidation is a chemical reaction where an element such as iron is exposed to air causing an oxide to form,
such as rust. Oxidation more often occurs in warm, moist climates when left exposed for long periods of
time.
7. In what climate does chemical weathering occur the fastest?
Chemical weathering occur the fastest in warm, humid climates. EX: tropical rain forest
8. In what climate does mechanical weathering occur the fastest?
Mechanical weathering occur the fastest in cold, humid climates. EX: temperate forest – where I live
9. What is humus? Be specific.
Humus is the dark, organic material formed in soil from the decayed remains of plants and animals.
10. Why is humus so important to soil?
Humus provides the nutrients that many soils are missing and are important for plant growth.
11. What causes leaching?
Leaching is the movement of water through the horizons or soil layers. ( bedrock, clay, silt, sand)
12. What is soil fertility? Explain.
Soil fertility is the ability of soils to hold nutrients and share them with plants.
13. What is contour plowing and when is it used?
Contour plowing is a practice used in farming where they plow across the slope of a hill. This method is
used to prevent soil erosion and conserve rainfall. The rows act as a series of dams instead of a series of
rivers.
14. What is terracing and when is it used?
Terracing is used on steep hills to prevent erosion from heavy rains. This process changes one steep field
into several smaller, flatter fields.
15. What is no-till farming?
No-till farming prevents erosion by providing ground cover that reduces water run-off.
16. What are cover crops?
Cover crops are leafy green vegetation used between harvests to replace nutrients and to prevent soil
erosion.
17. How does crop rotation help soil?
By planting two different crops on the same plot of land, in alternating years, this allows the soil to recover
by slowing down the depletion of nutrients from the soil. This happens because different plants use
different nutrients.
18. What is differential weathering? Describe what happened to Devil’s tower.
Differential weathering is the process by which softer, less weather resistant rock wears away and leaves
harder, more weather resistant rocks behind. Devil’s Tower is the harder rock (granite) more resistant rock
left behind when the softer rock was weathered away.
19. What are the 4 agents of erosion?
The four agents of erosion are ice, gravity, wind, and water.
20. Define erosion and deposition.
Erosion is the process by which wind, water, ice, or gravity transports soil and sediments from one location
to another. Deposition is the process by which material is laid down or dropped.
21. What is mass movement?
Mass movement is defined as the downward movement of rocks and rock fragments downhill. This happens
as a result of gravity.
22. What occurs most often, slow or fast movement? (Explain)
Slow movement occurs more often than fast movement of landslides or rock falls. We do not always see or
feel the slow movement of materials.
23. Describe creep.
Creep is the slow, gradual downhill movement of weathered rock materials.
24. Describe the difference between a rock fall and a landslide.
A landslide is the sudden, rapid movement of rocks and soil down a slope. A rock fall is a group of loose
rocks that fall down a steep slope. Gravity precipitates both events (causes them to occur).
25. What type of glacier covers a large area of land?
A continental glacier is the largest glacier that can cover a continent.
26. What is saltation? How is it different from abrasion?
Saltation is the leaping movement of sand size particles in the direction that the wind is blowing. The
particles are transported in a fluid medium (wind) over an uneven surface. It differs from abrasion because
abrasion is the grinding and wearing away of a rocks surface through the mechanical action of other rocks
or sand particles.
27. How do dunes move? (describe by discussing wind)
Sand dunes are masses of loose sand that move across the ground by wind. The grains are blown up the
windward side of a dune until they reach the top; then they drop down into the shelter of the lee (the side
away from the wind). Other grains are blown up and over, burying the first. This continued action moves
the dune across the landscape.
28. How do beaches form? How do waves weather and erode rock?
Beaches from when waves deposit materials (sand, rock fragments, dead coral, and shells) on the shoreline.
Energy is released from the waves causing rock to break down, eventually forming sand. Water from
breaking waves rush into crack in rocks, helping break them further.
29. Does erosion ever stop? Defend your answer.
Erosion never stops. It’s always occurring.
30. What is the difference between a mudflow and a lahar?
A mudflow is a type of rapid mass movement (or mass wasting) that is comprised of saturated particles
formed from loose soil and water.
A lahar is an Indonesian word meaning "mudflow." A lahar is a form of a mudslide, triggered most often by
a volcanic eruption, which flows downslope. The volcanic eruption suddenly melts the ice, liquefies the soil
and volcanic ash to produce a hot mudflow.