weathering and mass movement
hydrolysis
A form of chemical weathering where there is a chemical reaction of a substance with water.
oxidation
A form of chemical weathering where there is a chemical reaction of an iron bearing substance with oxygen.
glacier
A large mass of moving ice and snow on land
river
A large, flowing body of water that usually empties into a sea or ocean.
soil horizon
A layer of soil that differs in color and texture from layers above and below it
soil
A loose mixture of rock fragments, organic material, water, and air that can support the growth of vegetation
parent rock
A rock that becomes something else -- in this case, soil.
windbreak
A row of trees planted to block the wind and prevent soil erosion.
slump
A type of mass movement that occurs when a mass of material moves down a curved slope
surface area
Although pieces of rock continue to get smaller each time a rock breaks apart, *more surface is exposed and surface area increases*. Surface area refers to the amount of the material exposed.
beach
An area of wave-washed sediment along a coast.
mass movement
Any one of several processes by which gravity moves sediment downhill.
living things that live in soil
Bacteria, fungus, earthworms, moles, and ants
abrasion
Bumping and breaking up of rocks as the collide. Rocks become *smaller, rounder and smoother.*
soil properties
Can be observed (such as soil profile, composition, texture or particle size), or measured, (such as permeability and pH).
carbonation
Carbonic acid in rain causes minerals to dissolve. Ex. marble gravestones.
particle size
Classified by size ranging from coarse sand to very fine sand to silt, and finally to clay
soil formation factors
Climate, parent material, organisms, slope, time
organic
Comes from a living thing
inorganic
Comes from a non-living thing
desertification
Degradation of land, especially in semiarid areas, primarily because of human actions like excessive crop planting, animal grazing, and tree cutting.
texture
Depends on the size of individual soil particles and is determined by the proportions of particle sizes that make up the soil
soil composition
Describes how soil is a mixture of rock particles, minerals, decayed organic material, air, and water
differential Weathering
Different parts of a rock weather at different rates
permeability
How freely water flows through open spaces between soil particles
sand dune
Large deposits of sand dropped when the wind stopped blowing. The location of one can shift frequently.
sand
Largest soil particle.
silt
Medium soil particle
soil erosion
Movement of soil components, especially topsoil, from one place to another, usually by wind, flowing water, or both. This natural process can be greatly accelerated by human activities that remove vegetation from soil.
agents of erosion
Natural forces include: moving water, glaciers, waves, wind and gravity.
frost wedging
Occurs in climates with freezing and thawing temperatures; water gets into cracks and creases of rock. Water expands when it freezes and causes cracks in rocks to get bigger and break apart. Ex: pot holes.
chemical weathering
Occurs on the surface of rocks and changes the composition of the material. This causes rocks to weaken and makes it easier for them to break apart (physical weathering). Dominates in warm moist climates.
rockfall
Occurs when rocks or rock fragments fall freely through the air
pores
Open spaces between the soil particles that allow water to flow through
frost action
Physical weathering when melt water seeps into rock, freezes, expands, and breaks a rock.
water erosion
Process that moves WAVES to shape the land creating new land forms
wind erosion
Process that uses WIND to move sand to create new land forms
mudflow
Quickly moving downhill flow of soil and rock fragments containing a large amount of water
acid rain
Rain polluted with emissions from fossil fuels (oil, coal, & natural gas).
deflation
Removal of loose material from Earth's surface by wind.
Onion Skin
Rock expands in heat during day and contracts when cool at night. Constant process causes outer rock to 'peel' off
physical (echanical) weathering
Rocks are broken up into fragments; does not change the composition of the rock but it does create more *surface area*. The dominant climate condition for this type of weathering is cold and moist.
rockslide
Rocks do not fall freely, but slide down a slope
root action
Roots grow into and under rocks and pry them apart causing cracks to get bigger. Ex: cracks in the sidewalk.
earthflow
Slow-moving downslope movement of water-saturated, clay-rich sediment, most characteristic of humid regions
clay
Smallest soil particle.
gravel
Soil particles that are larger than 2 mm
loam
Soil that is an even mix of sand, silt, and clay. Loam is the best for growing crops.
soil profile
Soils form in layers, or horizons, and all the layers make up this
exfoliation
Surface of the rock "peels" off. Unloading - caused by uplift and exposure of rock that was once deep underground and decreases pressure on rocks.
weathering
The breaking down of rock into smaller and smaller pieces by wind, water and ice.
gravity
The force that pulls rock and other materials downhill
abrasion
The grinding away of rock by other rock particles carried in water, ice, or wind
soil horizon
The layer of soil that differs in color and texture from the layers above or below it.
deforestation
The loss of forest cover in a region that results from the trees in a forest being destroyed faster than they can grow back.
rate of weathering
The most important factors that determine the rate at which weathering occurs are the type of rock and the climate. Rocks that are permeable have tiny connected holes in them, so materials can weather them down at a fast rate ( water seeps through)
porosity
The percentage of the total volume of a rock or sediment that consists of open spaces.
erosion
The process by natural forces of moving rock and soil from one place to another
deposition
The process where agents of erosion deposit, or lay down, sediment. It changes the shape of the land.
avalanche
The rapid movement of snow and ice down the side of a mountain.
humus
The remains of dead plants and animals found in the soil.
creep
The very slow downhill movement of rock and soil.
loess
Thick deposits of windblown dust.
A Horizon
Topsoil. Contains lots of humus and micro-organisms.
hydration
Water weakens the rock and the rock crumbles. Ex: feldspar becomes clay.
triggers of mass movement
Water, oversteeped slopes, earthquakes, removal of vegetation
sediment
Weathered pieces of rock, soil, and/or remains of dead plants and animals
landslide
a slide of a large mass of dirt and rock down a mountain or cliff
C Horizon
a soil horizon; made up of larger pieces of rock that have not undergone much weathering
biological weathering
any weathering that's caused by the activities of living organisms.
mechanical weathering
breaking down of rocks by physical forces, like pressure, ice wedging, freezing and thawing
mass erosion
downhill movement of weathered materials due to the gravity (landslides,mudflows,earthflow and creep.
C horizon
horizon made of rock fragments on top of unweatered bedrock
regolith
layer of weathered rock fragents covering much of the earths surface
slide
mass movement that occurs when a block of material moves suddenly along a flat, inclined surface
flows
mass movements of material containing a large amount of water, which move downslope as a thick fluid
major soil components
mineral matter, humus, water, and air
most important factors of soil formation
parent material, time, climate, organisms, and slope
angular rock
rocks that are not smooth - usually formed from gravity/ mechanical weathering
soil texture
size of soil particles; sand, silt, clay (largest to smallest).
oversteepened slope
slope with steepness that exceeds the stable angle
residual soil
soil that forms on bedrock
transported soil
soil that forms on unconsolidated deposits from which its parent material was moved from another location by gravity, water, wind, or ice
bedrock
solid unweathered rock lying beneath surface deposits of soil
B horizon
subsoil; contains fine clay particles washed out of the A horizon
biological activity
the activities of organisms, including plants, burrowing animals, and humans that can cause mechanical and chemical weathering
water
the most important agent of chemical weathering
differential weathering
the process in which different parts of a rock mass weather at different rates
parent material
the starting material of soil consisting of rock or sediment that is subject to weathering
A horizon
topsoil horizon that is generally gray to black, contains the remains of living things (humus)