Soil Science Chapter 2
Eluviation or clay, iron and other materials is the principal process responsible for the formation of an E horizon.
True
Residual parent materials have generally been subjected to weathering for a longer period of time than have lacustrine or alluvial parent materials.
True
Secondary minerals are recrystallized products of the chemical breakdown and/or alteration of primary minerals.
True
Residual parent materials are best described as ___________.
materials formed by weathering of rocks and minerals in place.
Residual parent materials are best described as ____________.
materials formed by weathering of rocks and minerals in place.
The transformation of gneiss into smaller mica, quartz, and feldspar pieces is an example of ________.
physical weathering
Glacial till is laid down by melt waters gushing out from the front of glaciers.
False
Hydrolysis involves the splitting of water into its H+ and OH- components while hydration attaches intact water molecules to a compound.
True
Igneous rocks are formed when molten magma cools and solidifies.
True
Minerals containing iron are generally more resistant to chemical breakdown than minerals that contain CaCO3.
True
Organic deposits are common in areas where water ponds for extended periods of time.
True
The C horizons are generally more completely weathered than the other horizons.
False
Weathering of rocks usually is most intense in the center of a rock fragment, and gradually decreases toward the outside.
False
A soil developed in transported parent materials will likely have properties related to the properties of the rock below the C horizon.
False.
Glacial till can be recognized by the distinct layering of different kinds of particles.
False.
Soils developed in wind-blown parent materials such as loess are generally of little agricultural value.
False
In which of the following horizons has the process of illuviation most likely occurred?
B Horizon
Silicate clay accumulation is most common in the ________________.
B Horizon
In most B horizons on of the dominant processes of soil formation has been eluviation.
False
The parent materials for most coastal plain soils are residual in nature.
False
The topmost horizon in most humid region forest soils is the A horizon.
False
The topmost horizon in most humid region forest soils is a A horizon.
Falsw
Which of the following statements is correct?
Lacustrine parent materials have been subject to weathering for shorter periods of time than residual parent materials nearby.
Which of the following statements is not correct?
Tropical forests protect the soil from excessive weathering
Which of the following statements is not correct?
Tropical forests protect the soil from excessive weathering.
Animals, insects and worms affect soil formation primarily by mixing the soil, which increases the porespace where air and water move.
True
Chemical weathering is accelerated by water, o2, and organic/inorganic acids moving down through the regolith.
True
Eluviation of clay, iron, and other materials is the principal process responsible for the formation of an E horizon.
True
The presence of rocks such as shale and sandstone indicate the existence of _____________.
ancient seas
The presence of rocks such as shale and sandstone indicate the existence of ______________.
ancient seas
Secondary minerals are most prominent in the __________fraction of soils.
clay
Which mineral is most resistant to weathering under humid temperate conditions?
gibbsite
Which of the following is not a secondary mineral?
hornblende
Granite is an example of an ______________.
igneous rock
The element most often involved in oxidation reactions as minerals weather is ______.
iron
The element most often invovled in oxidation reactions as minerals weather is _______.
iron
Igneous rocks can best be characterized as _______.
rocks formed when molten magma solidifies
Igneous rocks can best be characterized as _____________.
rocks formed when molten magma solidifies
Alluvial fans are usually characterized by ______ soils.
sandy and gravelly
Exfoliation is caused by changes in _______.
temperature
Exfoliation is caused by changes in ________.
temperature
Organic Deposits are common in areas where water ponds for extended periods of time.
true
Climate influences not only the rate of weathering but the type of native vegetation dominant in an area.
true.
Igneous, sedimentary, and metamorphic are three _______.
types of rocks
Which of the following is not considered on the 5 major factors of soil formation?
valence state
"Biotite --> clay-->iron oxides" represents a _____________.
weathering sequence