Mechanical Weathering
The process of breaking down rocks, minerals, and soil into smaller fragments without altering their chemical composition.
Mechanical Weathering
What is almost always a part of the cause of chemical weathering?
Water
Erosion removes or moves the weathered material to a new location
What is the loose covering of weathered material that lies on the earth's surface called?
SOIL!!!!
What are the distinct horizontal layers of of mature soil called?
Soil horizons
What is the starting material in soil formation called?
Parent material
This soil type forms at high altitudes or areas surrounding the Arctic Circle.
Polar Soil
What is one of the greatest threats to global food production?
Soil Erosion
Frost wedging, unloading, and biological activity are all parts of this kind of weathering.
Mechanical Weathering
This type of chemical weathering changes minerals into new minerals due to the chemical reaction to water.
Hydrolysis
What are the 3 main agents of erosion?
Water, wind, ice
What are the 4 main components of soil?
Mineral Matter, water, air, organic material
What is the O and A layer of soil called where most of the nutrients needed for plant growth are located?
Topsoil
What are 2 factors that may increase the rate at which soil is formed?
temperature and humidity
What is the permanently frozen material of the polar soils called?
Permafrost
What is one major cause of soil erosion?
Poor agricultural practices or human activities
Tree roots exerting force to widen cracks is what specific kind of weathering.
Biological Activity
What kind of chemical weathering occurs when atoms or ions lose electrons such as iron forming rust?
Oxidation
What are the narrow, shallower channels on the hillsides that are formed by rain called?
Rills
What 3 components are considered when looking at the soil's texture?
Sand, silt, clay
Which layer of soil contains the parent material?
C Layer
What are the first organisms to live on the surface of bare rocks called?
Lichens
Which soil is the most fertile and contains the most agricultural areas?
Temperate Grasslands
What might farmers do to prevent wind from eroding their fields?
Plant trees as wind breaks
What kind of mechanical weathering may create a domed surface from sheets of rock that "peel away" from fracturing of rocks due to the reduction of pressure of overlying rocks that are eroded away.
Unloading
Why does chemical weathering occur more quickly when mechanical weathering has fractured rock into smaller pieces?
The surface area of the rock increases
What agent of erosion creates mushroom shaped pillars in sandy, arid areas?
Wind
What is the space in soil called between mineral grains where water and air are found?
Pore spaces
What is another name for the B layer?
Subsoil
What do lichens produce to speed up the chemical weathering of rocks?
Acid
Which type of soil is surprisingly poor in helpful organic matter due to heavy rainfall removing water soluble minerals needed for nutrients?
Tropical soils
What is it called when once productive lands have become increasingly desert-like through drought or improper use?
Desertification
What are the piles of broken pieces of rock that accumulate on the slopes of mountains due to frost wedging called?
Talus
What causes each chemical weathering process to occur at faster rates?
Acid Rain
What is it called when rocks weather at different rates depending upon the location, climate, and exposure.
Differential Weathering
What is the decayed organic material in soil called?
Humus
What is the accumulation of clay called that forms a compact layer in the B horizon that keeps water from reaching deeper layers?
Hardpan
Why might a volcano have vegetation growing in some lava flows and not others?
Some lava flows may have been formed hundreds of years earlier allowing for soil formation and vegetation growth
What happens to tropical soil if too many trees are removed from the forests?
The clay in the soil bakes and becomes very hard
What type of soil conservation might a farmer use that forces water to run sideways along a hillside rather than in rills running straight down?
Contour plowing