Geol. 1403/Cook quiz 6 part I

Helpfulness: 0
Set Details Share
created 8 days ago by Devalon_N_Burk
2 views
book cover
GEOL
Chapter 6
updated 1 day ago by Devalon_N_Burk
Subjects:
geology, science
show moreless
Page to share:
Embed this setcancel
COPY
code changes based on your size selection
Size:
X
Show:
1

Clay minerals formed from gabbro or diorite bedrock illustrate which kind of weathering?

chemical

2

Why is the humus layer typically thicker in a cool , temperate, forest soil than in a tropical rainforest soil?

Less humus is produced in the cool, temperate forest but the rate of decay and oxidation is slower than in a tropical rainforest.

3

Frost wedging is the major weathering process contributing to the formation of which regolith material?

talus slopes

4

What portion of an angular, fracture-bounded granitic block shows the highest rate of weathering?

the edgesand corners

5

What describes a characteristic process in the formation of a pedalfer soil?

iron oxides and aluminum-rich clays are precipitated in the B-horizon

6

In the Rocky Mountain region of the U.S., north-facing slopes (downhill direction is toward the north) are typically more moist and heavily forested than south-facing slopes. Why?

north-facing slopes receive about the same amount of precipitation as south-facing slopes; less moisture evaporates from north-facing slopes.

7

Clay minerals, silica (SiO2), and disolved potassium bicarbonate in the soil water are products of what process?

chemical weathering of orthoclase feldspar

8

What two factors speed up rates of chemical reaction and weathering in rocks and soils?

warm temperatures; verymoist

9

In terrain with steep hill slopes, which crop and cultivation technique will minimize soil erosion?

apples, land between the trees is planted in grass and not cultivated.

10

From the land surface downward to the unweathered bedrock, what is the correct order of the different soil horizons?

O, A E, B, C, bedrock

11

What statement concerning mechanical weathering is not true?

Involves a major change in the mineral composition of the weathered material

12

The finely divided red, brown, and yellow soil-coloring materials originate by what process?

Precipitation of iron oxides during chemical weathering processes

13

What term describes a soil formed by weathering of the underlying bedrock?

residual

14

What best describes the "Dust Bowl"?

areas of severe wind erosion on the Great Plains , 1930s.

15

What is an important, mechanical wethering process for enlarging fractures and extending them deeper into large boulders and bedrock?

frost wedging

16

What best desribes sets of fractures in relatively fresh bedrock, such as granite, that are roughly parallel to the land surface?

sheeting fractures

17

Assume that water filling a crack in a rock undergoes cycles of freezing and melting. What statement is true?

water expands as it freezes, causing the crack walls to be pushed apart.

18

What statement best describes erosion?

the process by which weathered rock and mineral particles are removed from one area and transported elsewhere.

19

Quartz weathers readily to aluminum-rich clay minerals.

false

20

Abundant moisture and warm temperatures result in high rates of chemical weathering.

true

21

Feldspars commonly decompose during wethering to caly minerlas, silica, and soluable constituents.

true

22

Humus is a concentration of decaying, organic matter in the B-horizons of lateritic soils.

false

23

Calcite a major component of some monumental and building stones, slowly dissolves in weakly acidic waters.

true

24

Like most other liquids, water decreases in volume when it freezes.

false

25

Chemical weathering in bedrock below the land surface often begins along joints and sheeting fractures.

true

26

Removal of soluable chemical constituents from a soil is termed leaching.

true

27

Oxidation of iron is an important chemical weathering process for ferromagnesian silicate minerals like olivine and biotite.

true

28

Sheeting is mainly a process of mechanical weathering.

true

29

Sheeting fractures and exfoliation domes commonly develop in areas with soft, highly fractured bedrock.

True

30

Quartz is quite resisitant to weathering and is an important component of sands in riverbeds and on beaches.

true

31

Very fine-grained iron-oxide particles account for nearly all red, yellow and brown soil colors.

true

32

32.) First level of soil layer is the ____.

(e) O horizon

33

33.) Second level of soil layer is the ____.

(a) A horizon

34

34.) Third level of soil layer is the ____.

(b) B horizon

35

35. Fourth level of soil layer is the ____.

(c) C horizon

36

36.) Fifth level of soil layer is the ____.

(d) bedrock

37

At which location would the thickest residual soil develop?

D

38

At which location would the greatest amount of frost wedging occur?

A

39

A which location would the thickest transported soil develop?

B

40

At which location would there be the most unconsolidated deposits?

C