Deck 2: Formation of Soils From Parent Materials

Question 1

"Biotite-->clay-->iron oxide" represents a ________.

A) catena
B) weathering sequence
D) both A and B
E) none of the above

Answer 1

B

Question 2

Organic matter accumulation is most pronounced in the ____.

A) O horizon
B) A horizon
C) E horizon
D) B horizon
E) C horizon

Answer 2

A

Question 3

Glacial till is a term used to describe parent materials that:

A) were transported by water gushing from glacial fronts.
B) were laid down in the bottom of former glacial lakes.
C) were transported by high winds during glacial periods.
D) are sorted by rapidly flowing melt waters.
E) contain a heterogeneous mixture of mineral debris dropped by receding glaciers.

Answer 3

E

Question 4

Igneous rocks can best be characterized as:

A) rocks formed when molten magma solidifies
B) rocks containing both feldspars and micas
C) rocks formed from the recrystallization of sedimentary material
D) rocks containing a mixture of primary and secondary minerals
E) rocks found primarily near volcanoes.

Question 5

Igneous, sedimentary, and metamorphic are three _________.

A) types of rocks
B) basic classes of soils
C) master horizon names
D) forms of minerals
E) processes of weathering

Question 6

Which of the following is not considered one of the five major factors influencing soil formation?

A) native parent materials
B) living organisms
C) climate
D) valence state
E) topography

Question 7

The reaction: mica + H₂O Æ K⁺ + OH^- + acid clay is an example of ________.

A) chemical weathering
B) physical weathering
C) exfoliation
D) carbonation
E) both A and C

Question 8

Which mineral is most resistant to weathering under humid temperate conditions?

A) dolomite
B) muscovite
C) gypsum
D) gibbsite
E) biotite.

Question 9

Secondary minerals are most prominent in the fraction of soils.

A) organic
B) sand
C) silt
D) clay

Question 10

Silicate clay accumulation is most common in the ____.

A) A horizon
B) B horizon
C) C horizon
D) O Horizon
E) E horizon

Question 11

Residual parent materials are best described as __________.

A) materials formed under organic residues.
B) materials formed by weathering of rocks and minerals in place.
C) materials transported from one location to another by water, ice or wind.
D) materials more dominant in Iowa than in the Southern United States.
E) upland materials formed with relatively little chemical weathering.

Question 12

Which of the following statements is not correct?

A) Grasslands are found in semi-arid and sub-humid areas.
B) Coniferous forests are found mostly in cool humid areas.
C) The type of native vegetation is controlled primarily by climate.
D) Dense forests are found soil profiles have prominent O horizons.
E) Tropical forests protect the soil from excessive weathering.

Question 13

Which of the following is not a secondary mineral?

A) silicate clay
B) microcline
C) calcite
D) hematite
E) gypsum.

Question 14

In which of the following horizons has the process of illuviation most likely occurred? 14

A) O horizon
B) C horizon
C) A horizon
D) E horizon
E) B horizon

Question 15

The presence of rocks such as shale and sandstone indicate the existence of _______.

A) a high water Table
B) ancient seas
D) iron-rich minerals
E) highly weathered soils

Question 16

The transformation of gneiss into mica, quartz, and feldspar crystals is an example of:

A) physical weathering
B) chemical weathering
C) disintegration
D) hydrolysis
E) both A and C

Question 17

The element most often involved in oxidation reactions as minerals weather is _____.

A) copper
B) silicon
C) aluminum
D) magnesium
E) iron

Question 18

If you wanted to find a soil where physical weathering dominated over chemical breakdown you would be most apt to find it in ______.

A) a desert region of Arizona B. a humid region in Brazil
C) the hill lands of Georgia
D) a lacustrine deposit in Minnesota
E) a coastal plain area of Delaware

Question 19

Mechanical weathering processes result in:

A) the decomposition of primary minerals
B) the hydrolysis of minerals through frost action
C) the disintegration of rocks due to differential expansion of minerals
D) the oxidation of iron and manganese compounds

Question 20

Which of the following statements is correct?

A) Soils on hillsides tend to be deeper than those on level lands.
B) Lacustrine parent materials have been subject to weathering for shorter periods of time than residual parent materials nearby.
C) Limestone parent materials enhance the process of acidification.
D) Nutrient cycling in forested areas contributes little to soil formation.
E) Calcium carbonate accumulation is more prominent in humid than in arid regions.

Question 21

Residual parent materials have formed in place and have not been transported from one area to another.

Question 22

The A horizons are more apt to be cultivated than the E horizons.

Question 23

Iron and aluminum oxides are major components of igneous rocks.

Question 24

Living organisms affect soil formation primarily by their constraining the level of oxygen in the soil.

Question 25

Hydrolysis involves the splitting of water into its H⁺ and OH^- components while hydration attaches intact water molecules to a compound.

Question 26

The presence of iron in a mineral generally increases its resistance to chemical breakdown.

Question 27

Marine sediments are typical parent materials in coastal plain areas.

Question 28

Alluvial parent materials are those that have been laid down in former lake bottoms.

Question 29

The mixed angular gravel, rock, and soil found at the foot of a slope is typical of what type of parent material?

A) eolian
B) colluvial
C) fluvial
D) glacial
E) lacustrine

Question 30

Alluvial fans are usually characterized by ______ soils.

A) sandy and gravelly
B) clay textured
C) poorly drained
D) nearly level

Question 31

Residual parent materials have generally been subjected to weathering for a longer period of time than have lacustrine or alluvial parent materials.

Question 32

Igneous rocks are formed when molten magma cools and solidifies.

Question 33

Climate influences not only the rate of weathering but the type of native vegetation dominant in an area.

Question 34

Chemical weathering is accelerated by water, oxygen, and organic and inorganic acids moving down through the regolith.

Question 35

Exfoliation is caused by changes in _________.

A) hydration
B) oxidation
C) temperature
D) carbon dioxide dissolution
E) all of the above

Question 36

Glacial till is laid down by melt waters gushing out from the front of glaciers.

Question 37

Secondary minerals are recrystallized products of the chemical breakdown and/or alteration of primary minerals.

Question 38

Organic deposits are most common in areas where water flow over the soil surface is restricted.

Question 39

The O horizons of a soil are dominantly organic horizons occurring above mineral horizons.

Question 40

Sandstones are good examples of metamorphic rocks.

Question 41

Eluviation of clay, iron, and other materials is the principal process responsible for the formation of an E horizon.

Question 42

The topmost horizon in most humid region forest soils is the A horizon.

Question 43

The parent materials for most coastal plain soils are residual in nature.

Question 44

A soil developed in transported parent materials will likely have properties related to the properties of the rock below the C horizon.

Question 45

In most B horizons one of the dominant processes of soil formation has been eluviation.

Question 46

Weathering of rocks usually is most intense in the center of a rock fragment, and gradually decreases toward the outside.

Question 47

Even if all the glaciers present today in the world were to melt, the melt water would have no measurable effect on the level of the world's oceans.

Question 48

Soils developed in wind-blown parent materials such as loess are generally of little agricultural value.

Question 49

Sapric and fibric are terms used to describe peat parent materials.

Question 50

Glacial till can be recognized by the distinct layering of different kinds of particles.

Question 51

The C horizons are generally more completely weathered than the other horizons.

Question 52

A soil developed in residual parent materials will likely have properties related to the properties of the rock below the C horizon.