Unit 13 Flashcards
Weathering
process that leads to another type of material found on Earth’s surface (soil)
Denudation
A) Overall effect of all disintegration, wearing away, and removing of rock material
B) 3 types of activities: weathering, mass wasting, erosion
C) Impacts building/structures as well as natural landscapes
weathering agents
water, ice, wind, acids, salt, plants, animals, changes in temperature
Mass Wasting
material that falls under the influence of gravity with little or no transporting agent
Erosion
A)processes that move material to another place under the influence of transporting agents
B)some rivers can have either an alluvial fan or delta (deposit of sediment
transporting agents (erosion)
water (river: move material downstream), ice, wind(winds from Africa get blown to North America)
Alluvial Fan
weathered material that spread out over a plain; sits at bottom of valley
Delta
river flows into large body of water (Mississippi river)
ice
a glacier is a body of ice formed on land that is in motion: not readily apparent over short periods
Weathering structures
A) great sphinx
B) Grand Canyon (water was agent)
C) analope canyon
Mechanical Weathering
destruction of rocks through the imposition of stress (pressure)
A) frost wedging
B) salt wedging
C) thermal expansion (desert rocks, lightening, forest fires)
Chemical Weathering
breaking down ricks through a chemical rection
A) change the materials that make up rocks
oxidation ( chemical weathering)
oxygen combines with metallic elements in minerals to form new products known as “iron oxides” (rust)
- iron oxides: easy to break down, reddish brown to orange minerals, rust like coating
- produces acid that dissolves rock
Carbonation (chemical weathering)
CO2 gas dissolves in water to form an acidic solution
-acidic solutions are good at attacking and dissolving rocks
Biological Weathering
Weathering from plants and animals
A) Tree roots: roots crack through rock
B) Animals burrowing into ground: break apart rock and soil
-Weathering processes do not work independently; occur simultaneously and work together to break down rocks
-weathering is a natural process, but humans speed it up
A) some types of air pollution increase the rate of weathering: burning coal, natural gas, and oil release gas(Nitrogen oxide and Sulfur Dioxide)
B) chemicals combine with sunlight and moisture: form into acids and fall back to earth as acid rain
soil
Are comprised of broken fragments of rock called DETRITUS
A) weathering is the act of creating these fragments
B) fragments come from variety of rocks and are produced from a combination of weathering processes
Infiltration rate
amount of water able to enter the soil in a specified time period
Pore Size
space between soil particles
Sand
relatively large particles, high infiltration rate, large pores, vegetation struggles to grow,
Clay
Most fine type of soil, low infiltration rate, small pores, large quantities can make soil heavy and dense, plant roots cannot penetrate it
Silt
more fine than sand but more coarse than clay, higher infiltration rate than clay but lower than sand, pore size in between clay and sand, common in floodplains, most prominent component of mud, good for plants
Loam
type of soil that is a combination of sand, silt, and clay. There are many different variations, which are determined by composition (percentage of sand, silt, and clay)
