Chapter 5 Flashcards
Weathering
The group of processes that change rock at or near earth’s surface.
Erosion
The picking up or physical removal of rock particles kind of like sand and the ocean.
transportation
The movement of eroded particles by agents such as rivers, waves, glaciers or wind.
mechanical Weathring
The physical breakdown of rocks into smaller particles.
Chemical Weathering
The decomposition of rock from exposure to water and atmospheric gases. As rock is decomposed this way ne chemical compounds are formed.
Spheroidal Weathering
Weathering affects that produce rounded rock from an initial blocky shape.
Differential Weathering
Varying rates of weathering resulting from some rocks in an are being more resistant to weathering than others.
Pressure Release
A type of mechanical weathering that causes rocks to crack when overburden is removed.
Sheet Joints
Cracks that develop parallel to the outer surface of a large mass of expanding rock, as pressure is released during unloading.
Frost Action
Mechanical weathering of rocks by freezing water.
Frost heaving
Lifts rock and soil vertically by the expansion of freezing water.
Frost Wedging
A type of frost action in which the expansion of freezing water pries a rock apart.
what are the two main types of frost action
Frost Action and Frost Wedging.
What are weathering products?
New minerals that have adjusted to physical and chemical conditions at or near earths surface.
What is the most effective agent of chemical weathering?
Acid
What kind of ions do acids give of when they are breaking down?
Hydrogen.
What is Carbonic Acid?
A weak acid that is made up of water and carbon that dissociates into the hydrogen ion and bicarbonate ios.
What is Solution Weathering?
When minerals are completely dissolved by chemical weathering this is referred to as Solution Weathering.
How do caves form from Solution Weathering?
Caves can form underground when flowing groundwater dissolves the sedimentary rock limestone, whis is mostly Calcite.
Clay Mineral
A hydrous aluminum silicate with sheet-silicate structure like that of mica.
What are chemical compounds that five of hydrogen ions when they break down in water?
Acids
What is solution weathering
When rocks are chemical broken down by slightly acid water.
What does the solution of Calcite contain
Calcium ions and Bicarbonate ios.
What does the solution of Ca-feldspar
CA2+ and HCO3 ions as well as silica.
Definition of Regolith
The loose, unconsolidated material that covers most of earths land surface.
Definition of soil
A layer of weathered unconsolidated material that contains organic matter and is capable of supporting plant froth.
What is the average soil composed of
45% rock and mineral fragments, 5 decomposed organic matter or humus, and 50& pore space.
What are soil Horizons?
Layers of soil.
What is the O Horizon?
Dark-colored soil later that is rich in organic material and forms just below surface vegetation.
What is the A Horizon?
A dark colored soil layer that is rich in organic matter and high in biological activity, both plant and animal.
E Horizon
Soil horizon that is the zone of leaching, characterized by the downward movement of water and removal of fine grained soil components.
What is humis
Highly decomposed biological matter.
B Horizon
The layer under the E Horizon and often referred to the zone of accumulation. This later is often quite clayey and stained red or brown by hematite and limonite
What is the Hard Pan?
it is a layer inside of the b Horizon made up of clay minerals, silica , and iron. It is very difficult to dig or through and may even be too hard for backhoes to dig through.
C Horizon
incompletely weathered parent material that lies below the B Horizon.
Residual Soils
Soil that develops directly from weathering of the rock below.
transported soils
Soils that do not develop from locally formed rock, but from regolith brought in from some other region.
How does the slope of a hill affect the formation of soil?
On slopes the soil tends to be thin because it can easily be moved down hill.
What is the largest factor in the formation of soil?
Climate
How does time affect soil formation?
At first the parent material determines the soil properties, but after a while other factors become more important and climate eventually predominates.
Paleosol
A soil that has been buried by lava flow, volcanic ash, windblown dust, glacial deposits, or other sediment is called a buried soil, or paleosol.
What is splash erosion
When raindrops strike unprotected soil like tiny bombs, dislodging soil particles.
sheet erosion
a thin sheet of running water that caries the dislodged soil particles away
rills
Tiny channels cut by water in soil.
Gullies
When rills deepen and merge into stream channels.
What are the three things that affect soil errosion?
Climate, Slope, and Vegetation.
What are some ways to conserve topsoil in the midwest?
Windbreaks, contour plowing, terracing, and crop rotation.
What are the three biggest factor that affect soil formation?
- Climate
- slope
- Temperature
Silt
between sand and clay in size.
What group of minerals is susceptible to oxidation of iron
Ferromagnesians
