SCC 200: The Formation of Soil

Floodplain deposits can be recognized by the distinct layering of different size and kinds of particles. Select one: True False

True

Hydrolysis involves the splitting of water into its H+ and OH- components while hydration attaches intact water molecules to a compound. Select one: True False

True

Igneous rocks are formed when molten magma cools and solidifies. Select one: True False

True

Marine sediments are typical parent materials in coastal plain areas. Select one: True False

True

Minerals that contact iron are more resistant to chemical breakdown than minerals that contain CaCO3. Select one: True False

True

Organic deposits are common in areas where water ponds for extended periods of time. Select one: True False

True

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

True

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

True

Sapric and fibric are terms used to describe peat parent materials. Select one: True False

True

Secondary minerals are recrystallized products of the chemical breakdown and/or alteration of primary minerals. Select one: True False

True

In which of the following horizons has the process of illuviation most likely occurred? Select one: a. E horizon b. O horizon c. A horizon d. C horizon e. B horizon

e. B horizon

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

False

Alluvial parent materials are those that have been laid down in former lake bottoms. Select one: True False

False

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. Select one: True False

False

Glacial till is laid down by melt waters gushing out from the front of glaciers. Select one: True False

False

In most B horizons one of the dominant processes of soil formation has been eluviation. Select one: True False

False

Iron and aluminum oxides are major components of igneous rocks. Select one: True False

False

Sandstones are good examples of igneous rocks. Select one: True False

False

Soils developed in wind-blown parent materials such as loess are generally of little agricultural value. Select one: True False

False

The C horizons are generally more completely weathered than the other horizons. Select one: True False

False

The parent materials for most coastal plain soils are residual in nature. Select one: True False

False

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

False

The topmost horizon in most cool-humid forest soils is the A horizon. Select one: True False

False, Correct, the "O" horizon is the top layer in a humid forest. The correct answer is 'False'.

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

True

Animals, insects and worms affect soil formation primarily by mixing the soil, which increases the porespace where air and water move. Select one: True False

True

Chemical weathering is accelerated by water, oxygen, and organic and inorganic acids moving down through the regolith. Select one: True False

True

Climate influences not only the rate of weathering but the type of native vegetation dominant in an area. Select one: True False

True

Eluviation of clay, iron, and other materials is the principal process responsible for the formation of an E horizon. Select one: True False

True

The A horizons are more apt to be cultivated than the E horizons. Select one: True False

True

The O horizons of a soil are dominantly organic horizons occurring above mineral horizons. Select one: True False

True

Which of the following statements is not correct? Select one: a. Tropical forests protect the soil from excessive weathering. b. The type of native vegetation is controlled primarily by climate. c. Coniferous forests are found mostly in cool humid areas. d. Grasslands are found in semi-arid and sub-humid areas. e. Where dense forests are found, soil profiles have prominent O horizons.

a. Tropical forests protect the soil from excessive weathering. b. The type of

The reaction: mica + H2O → K+ + OH- + acid clay is an example of ________. Select one: a. chemical weathering b. physical weathering c. exfoliation d. carbonation e. both A and C

a. chemical weathering

"Biotite → intermediary secondary mineral → iron oxide" represents a ________. Select one: a. weathering sequence b. catena c. toposequence d. both A and B e. none of the above

a. weathering sequence

Which of the following statements is correct? Select one: a. Nutrient cycling in forested areas contributes little to soil formation. 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. Soils on hillsides tend to be deeper than those on level lands. e. Calcium carbonate accumulation is more prominent in humid than in arid regions.

b. Lacustrine parent materials have been subject to weathering for shorter periods of time than residual parent materials nearby.

Organic matter accumulation is most pronounced in the ________. Select one: a. B horizon b. O horizon c. C horizon d. A horizon e. E horizon

b. O horizon

If you wanted to find a soil where physical weathering dominated over chemical breakdown you would be most apt to find it in ________. Select one: a. a lacustrine deposit in Minnesota b. a desert region of Arizona c. the hill lands of Georgia d. a coastal plain area of Delaware e. a humid region in Brazil

b. a desert region of Arizona

Glacial till is a term used to describe parent materials that ________. Select one: a. are sorted by rapidly flowing melt waters. b. contain a heterogeneous mixture of mineral debris dropped by receding glaciers. c. were transported by water gushing from glacial fronts. d. were transported by high winds during glacial periods. e. were laid down in the bottom of former glacial lakes.

b. contain a heterogeneous mixture of mineral debris dropped by receding glaciers.

Which mineral is most resistant to weathering under humid temperate conditions? Select one: a. muscovite b. gibbsite c. dolomite d. biotite e. gypsum

b. gibbsite

The element most often involved in oxidation and reduction reactions as soils weather is ________. Select one: a. magnesium b. iron c. silicon d. aluminum e. copper

b. iron

Residual parent materials are best described as ________. Select one: a. materials more dominant in Iowa than in the Southern United States. 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 formed under organic residues.

b. materials formed by weathering of rocks and minerals in place.

Igneous rocks can best be characterized as ________. Select one: a. rocks formed from the recrystallization of sedimentary material b. rocks formed when molten magma solidifies c. rocks found primarily near volcanoes. d. rocks containing a mixture of primary and secondary minerals e. rocks containing both feldspars and micas

b. rocks formed when molten magma solidifies

Igneous, sedimentary, and metamorphic are three ________. Select one: a. processes of weathering b. types of rocks c. basic classes of soils d. master horizon names e. forms of minerals

b. types of rocks

Which of the following is not considered one of the five major factors influencing soil formation? Select one: a. living organisms b. valence state c. topography d. climate e. native parent materials

b. valence state

Silicate clay accumulation is most common in the ________. Select one: a. O Horizon b. C horizon c. B horizon d. A horizon e. E horizon

c. B horizon

The mixed angular gravel, rock, and soil found at the foot of a slope is typical of what type of parent material? Select one: a. alluvial b. lacustrine c. colluvial d. eolian e. glacial

c. colluvial

Mechanical weathering processes result in ________. Select one: a. the oxidation of iron and manganese compounds b. the dissolution of primary minerals c. the disintegration of rocks due to differential expansion of minerals d. the hydrolysis of minerals through frost action

c. the disintegration of rocks due to differential expansion of minerals

Secondary minerals are most prominent in the ________ fraction of soils. Select one: a. sand b. silt c. organic d. clay

d. clay

Which of the following is not a secondary mineral? Select one: a. gibbsite b. silicate clay c. calcite d. hornblende

d. hornblende

Granite is an example of a(n) ________. Select one: a. secondary mineral b. eolian parent material c. primary mineral d. igneous rock e. sedimentary rock

d. igneous rock

Exfoliation is caused by changes in ________. Select one: a. oxidation b. hydration c. carbon dioxide dissolution d. temperature

d. temperature

The presence of rocks such as shale and sandstone indicate the existence of ________. Select one: a. iron-rich minerals b. old mountain ranges c. a high water table d. highly weathered soils e. ancient seas

e. ancient seas