_____ is the term used for the variety of processes that change the physical and chemical properties of rock exposed at the Earth's surface
Weathering
What is erosion?
The physical removal of rock particles by water, wind, or ice.
____ is the movement of eroded particles to another location
Transportation
The minerals that form as the products of chemical weathering are ______.
in equilibrium with the physical conditions at the Earth's surface
The two main categories of weathering are ___and _____.
mechanical and chemical
The primary agents of transportation are ____
wind, ice, and water.
The new minerals that form in response to chemical weathering are referred to as ____
weathering products
Match the components of soil with the roles they play.
-rock and mineral fragments
-clay
-humus
-pore spaces
Rock and mineral fragments= anchoring for plant roots
Clay=attraction of water molecules and nutrients
Humus= release of weak acids; production of nutrients
Pore spaces= circulation of air and water.
Which of the following are supplied to groundwater by the solution weathering of calcite?
bicarbonate ions and calcium ions
The lowermost portion of the soil profile consists of incompletely weatherer parent material. This layer, marked by a red arrow in the diagram, is known as the ____ _______.
C horizon.
Which mechanical weathering process is illustrated here?
Frost wedging
when a soil is buried and preserved, it can be useful for determining past climates and topography. this type of soil is called a(
n) ___.
paleosol
What is the term used for tiny channels cut into soil by running water?
rills
the dark-colored soil layer marked with a red arrow in this image is rich in organic matter and high in biological activity. it is referred to as the ___.
a horizon
Which of the following are products of chemical weathering of Ca-feldspar that are supplied to groundwater?
Calcium ions
bicarbonate ions
silica
Which of the following are factors that affect weathering?
- Temperature
-slope
-presence of water
-rock type
Which of the following are factors that affect the rate of soil erosion?
-Soil characteristics
-Vegetation
-Climate
-slope
The two main types of frost action are frost____ and frost____
wedging and heaving
A ___ mineral is a hydrous aluminum silicate with a sheet-silicate structure
clay
Some rocks form at depth. when the pressure of these rocks is reduced by erosion of overlying rocks, the underlying rock will expand and crack. This type of _____ weathering is know as pressure release.
mechanical
____ weathering is the decomposition of rock through exposure to water and atmospheric gases.
chemical
what is the name of the pale, shady horizon in the soil profile shown here?
E horizon
__ are chemical compounds that give off hydrogen ions when they break down in water
acids
A soil that develops on weathering granite is likely to be _____.
- composed of quartz, feldspar, and clays
- sandy in texture
-good for plant growth
A soil that develops from weathering of the bedrock beneath it is called a _____
residual soil
which soil horizon is marked with a red arrow in this photo
o horizon
How are soil horizons distinguished from one another?
composition and appearance
Mechanical
rock that formed at depth and is exposed at the surface due to unloading undergoes expansion and cracking. Cracks in rock are widened due to expansion of water when it freezes to ice.
chemical
Minerals exposed to acidic rain or groundwater are completely dissolved. Oxygen in the atmosphere combines with iron in ferromagnesian minerals to form oxides such as hematite.
the ____ ______ in this image are cracks that form parallel to the outer surface of the body of rock due to unlading of granite.
sheet joints
which of the following minerals is completely dissolved by chemical weathering
calcite
Changes in slope steepness can be the result of differential weathering of the bedrock. layers of rock that are more resistant to weathering form a ____ slope, while rocks that are less resistant to weathering form a ___ slope.
steep
gentle
The type of mineral matter contained in a soil is controlled by the ___ _____
parent material
sometimes, material leached down from the E horizon will form clay minerals, silica, and iron oxides that is very difficult to dig through. What is this layer know as?
Hardpan
When a mineral dissolves in the presence of carbonic acid, this type of chemical weathering is known as ____
solution weathering
what is the name for the removal of soil particles by water flowing over the landscape?
sheet erosion
Rocks exposed at the Earth's surface are subject to the processes of ____.
-transportation
-weathering
-erosion
A soil ____ describes soil horizons along a vertical cross section through a soil.
profile
When rock has been rounded by weathering from an initially blocky shape, the process is called ___ weathering
spheroidal
What is humus?
Highly decomposed plant matter found in the O horizon
The ____ ____ is often clay-rich and stained red or brown by hematite and limonite, which form from iron leached out of the overlying soil by downward percolation water
B horizon
An alkali soil forms when evaporation of soil water in a(n) _____ climate leads to heavy buildup of salts that can be toxic to vegetation
arid
How does frost heaving move rocks and soil vertically?
Water in the coil freezes and expands, pushing the ground surface upward.
Geologists reserve use of the term __ for the layer of weathered, unconsolidated rock and mineral fragments that contains organic matter and is capable of supporting plant growth.
soil
What does the term "topsoil" refer to?
The two upper horizons of a soil profile (O and A horizons)
Soil is classified into one of ___ orders depending on the characteristics of the _ in the soil profile
twelve
horizons
O horizon
uppermost layer; consists entirely of organic material
A horizon
organic material mixed with mineral matter
Topsoil
the two uppermost, organic-rich, layers
E horizon
pale, sandy layer, leached of clay and elements such as iron and calcium
B horizon
clay-rich layer stained red by hematite and limonite
C horizon
incompletely weathered parent material
A batholith exposed unloading will expand outward due to the reduction in pressure _____ develop parallel to the outer surface of the rock as it expands.
Sheet joints
what is the term used for the dislodging of soil particles by the impact of raindrops
Splash erosion
The ____ ____ is a dark-colored soil layer that is rich in organic matter and high in biological activity
A horizon
Rocks exposed on the Earth's surface are constantly being changed by environmental factors such as ____
-interaction with water
-temperature changes
-contact with air