1. Weathering and Soil Formation
Chapter 6

2. The breaking down of rocks and other materials at Earth’s surface is
WARM-UP #1
The breaking down of rocks and other materials at Earth’s surface is

3. ANSWER
weathering.

4. Freezing and thawing cause
WARM-UP #2
Freezing and thawing cause

5. ANSWER
Ice wedging

6. VOCABULARY
Weathering
Erosion
Uniformitarianism

7. weathering and erosion
Weathering – the process that breaks down rock and other substances at the Earth’s surface.
Erosion – forces of erosion carry the pieces away…..weathering and erosion work together to break down and carry away rocks on Earth’s surface.

8. Uniformitarianism – principles that operate today operated in the past
vocabulary
Uniformitarianism – principles that operate today operated in the past

9. Which is a cause of chemical weathering?
WARM-UP #3
Which is a cause of chemical weathering?

10. ANSWER
Acid rain

11. Mechanical weathering is faster in a climate that is
WARM-UP #4
Mechanical weathering is faster in a climate that is

12. ANSWER
warm

13. Mechanical weathering Abrasion Ice wedging
VOCABULARY
Mechanical weathering
Abrasion
Ice wedging

14. MECHANICAL WEATHERING
Mechanical weathering – weathering where the rock is broken into smaller pieces….each piece is still the same composition….mechanical weathering is a slow process

15. EXAMPLES
Freezing and thawing, release of pressure, plant growth, actions of animals, abrasion
Abrasion – grinding away of rocks by rock particles carried away by wind, water, ice, or gravity
Ice wedging – water seeps into cracks – expands when it freezes – ice is like a wedge that breaks the rock apart

16. When dead plants and animals decay, they form
WARM-UP #5
When dead plants and animals decay, they form

17. ANSWER
humus

18. A solid layer of rock under the soil is called
WARM-UP #6
A solid layer of rock under the soil is called

19. ANSWER
bedrock

20. VOCABULARY
Chemical weathering
Oxidation
Permeable

21. Chemical weathering
Process that breaks down rock through chemical changes………..causes are the action of water, oxygen, carbon dioxide, living organisms, and acid rain.

22. VOCABULARY
Oxidation – when iron combines with oxygen in the presence of water………….rust
Permeable – rock that is full of tiny holes…allows water to seep through easily….permeable rocks will weather quickly when exposed to chemical weathering.

23. In the United States, most of the eastern states are covered with
WARM-UP #7
In the United States, most of the eastern states are covered with

24. ANSWER
Forest soil

25. Living things that break down dead organisms are called
WARM-UP #8
Living things that break down dead organisms are called

26. ANSWER
decomposer

27. VOCABULARY
Soil
Bedrock
Humus

28. VOCABULARY
Soil – loose weathered material on Earth’s surface where plants can grow
Bedrock – solid layer of rock below the soil
Humus – decayed organic material in soil

29. Soil fertility is a measure of
WARM-UP #9
Soil fertility is a measure of

30. ANSWER
how good soil is for growing plants.

31. WARM-UP #10
Farmers leave dead plants in their fields in the soil conservation method called

32. ANSWER
conservation plowing.

33. VOCABULARY
Fertility
Loam
Soil horizon

34. VOCABULARY
Fertility – measure of how well the soil supports plant growth
Loam – soil made up of equal parts of sand, clay and silt
Soil horizon – is how the soil develops into layers ………the layers differ in color and texture

35. WARM-UP #11
The movement of rock pieces and other materials on Earth’s surface is called ____________________________.

36. ANSWER
erosion

37. WARM-UP#12
The kind of weathering that breaks rocks into smaller pieces is _____________weathering.

38. ANSWER
mechanical

39. VOCABULARY
Topsoil
Subsoil
Litter
Decomposers

40. TOPSOIL AND SUBSOIL
Topsoil – is horizon A ….crumbly, dark brown soil that is a mixture of humus, clay and other mixtures
Subsoil – is horizon B….clay and other particles washed down from horizon A…little humus

41. LITTER AND DECOMPOSERS
Litter – is what is left of the plant before it adds to humus…..leaves, roots, and the plant itself when it dies.
Decomposers – organisms that break down the remains of dead organisms into smaller pieces and digest them with chemicals.

42. WARM-UP#13
The scraping of rock by wind-blown pieces of rock is called __________________________.

43. ANSWER
abrasion

44. WARM-UP#14
The material on Earth’s surface in which plants can grow is ___________________.

45. ANSWER
soil

46. VOCABULARY
Sod – thick masses of tough roots at the surface of the soil……..keeps the soil in place and held onto moisture.
Natural resource – anything in the environment that humans use

47. The B horizon is also called _____________ .
WARM-UP #15
The B horizon is also called _____________ .

48. ANSWER
subsoil

49. In ______________ weathering, the makeup of rock changes.
WARM-UP #16
In ______________ weathering, the makeup of rock changes.

50. ANSWER
chemical

51. VOCABULARY
Dust Bowl – ruined farmland on Oklahoma and parts of the surrounding states…..caused by years of droughts and lots of plowing tuned the top soil to dust and it blew away.
Soil Conservation – management of the soil to prevent it’s destruction.

52. Different kinds of rock weather at different ___________.
WARM-UP #17
Different kinds of rock weather at different ___________.

53. rates

54. The last layer of soil to form is the _____ horizon.
WARM-UP #18
The last layer of soil to form is the _____ horizon.

55. C

56. PLOWING
Contour Plowing – plow the fields along the curve of the slope….slows runoff and preserves the soil from erosion.
Conservation Plowing – disturb the plant cover and soil as little as possible…dead weeds and stalks are left in the ground to help return soil nutrients.

57. CROP ROTATION
Farmers plant different crops in the field each year………helps maintain the nutrients in the soil

58. Loss of _____________ causes soil to lose its fertility.
WARM-UP #19
Loss of _____________ causes soil to lose its fertility.

59. topsoil

60. WARM-UP #20
One way to keep soil fertile is to grow a __________________ kind of plant every year.

61. different