Chapter 3 Weathering, Erosion, Deposition Flashcards
______ process is the reduction and change of the land surface via what three things?
gradational
- weathering, erosion/deposition, mass movement
____ builds landforms
____ breaks them down
tectonic
gradation
what affects the rate at which exposes rocks will weather and erode?
location and elements
rock type and strength
exposure time
the processes that fragment rock materials is called
weathering
examples of weathering
sunlight, wind, rain, snow, ice, freezing and thawing, effects of life forms
two types of weathering
physical and chemical
what is the difference between physical (mechanical) weathering and chemical weathering
physical does not change the chemical makeup of the rock
chemical changes the minerals via water, gas (CO2 and O2) and organisms
The processes of physical weathering have their greatest effect at _____ elevations and ____ latitudes.
high
Frost Wedging
Salt Weathering
Biophysical
Abrasion
Exfoliation
(Thermal Expansion)
What are these examples of?
Physical weathering (no chemical makeup is affected)
Physical weathering breaks rocks down into smaller pieces, or clasts—collectively called _____
debris
what is frost wedging
water goes into the joints of rocks, freezes, and expands
where does frost wedging occur? what are examples?
high mountains and latitudes such as himalayas and andes
what is the most important physical weathering in places that drop below freezing?
frost wedging
why does salt weathering occur in arid climate and coastal areas?
arid climates = high evaporation rates
coastal areas = rock exposed to sea spray
physical weathering that occurs in arid climate and coastal areas
salt weathering
what is salt weathering?
salt crystals grow in pores of rocks, exerting pressure as they grow
how does growth occur in salt weathering?
the rock is continually wetted with salt water, then dried
Are rounded pits or cavities on the surface of a rock that form via salt weathering
tafoni
weathering caused by any living organism
biophysical weathering
when plant roots that are seeking water grow into joints
root wedging
rocks and sediment grind against each other, wearing down surfaces over time (wind, water, ice)
abrasion
Layers or sheets of rock break away from the surface as a result of decreasing pressure or shifts in temperature
exfoliation
exfoliation is aka
peeling onion
chemical weathering changes the _____ in rock through ____ rxn mainly involving _____
minerals, chemical, water
chemical weathering occurs mainly on the ____ of the rock
surface
where is chemical weathering dominant
warm/humid environments
what type of weathering is dominant above freezing temps? below freezing?
above - chemical
below - physical (frost wedging)
what type of weathering? chemical or physical
Hydrolysis
Oxidation
Carbonation
chemical
how does hydrolysis work?
elements in water replace elements in the original material and creates a new substance
what type of minerals are softer and more easily eroded? (new or old?)
new
how does oxidation work?
oxygen atoms combine with minerals in rocks and weakens them
rocks containing ____ ____ compounds rusts (_____) into softer, (color) rock
iron oxide, oxidizes, reddish-brown
how does carbonation work
carbonate rock like limestone is dissolved in a carbonic acid solution and carried away
carbonation created “ “ landscapes
karst
steps of the karst process
Precipitation absorbs small amounts of carbon dioxide from the air & flowing water from soils
Forms a carbonic acid solution
Solution dissolves the calcium carbonate in limestone
Sediment transport moves the dissolved limestone away, leaving behind various landforms
what is mass movement
movement of rock, soil, snow, or ice downslope by gravity
the following are examples of what?
Landslides
Avalanches (snow & rock)
Flows (debris, mud, lahar)
Rockfall
mass movement ranges in _____
the faster the more ___
duration
dangerous
the gradual, imperceptible movement of soil or rock down a slope due to gravity
soil creep
the movement of weathered rock particles to be deposited elsewhere
erosion
what are examples of erosional agents
water, wind, ice, and waves
the movement of rock fragments (sediments) that have been weathered and eroded
sediment transport
what is the most important example of sediment transport?
stream flow (others include wind, glaciers, waves)
the laying down of sediment carried by wind, water, or ice
deposition
how was the grand canyon formed
Colorado plateau uplifted
Colorado river cut canyon
Erosion & Mass wasting of canyon walls
Oxidation
