Erosion
What is the difference between weathering and erosion?
Weathering breaks rocks into smaller pieces; erosion moves those pieces away.
Chemical weathering occurs when...
Chemical reactions dissolve or change the minerals in rocks.
What is mechanical weathering?
The process where rocks are physically broken down into smaller pieces without changing their chemical composition.
Small pieces that break off of rocks.
Sediments
Which two types of common weather conditions can break down exposed rock?
Wind and rain
Chemical weathering happens fastest under which conditions?
Abundant water
What type of physical weathering involves the roots of plants?
Root wedging
What determines the amount of runoff?
The amount of vegetation, the amount of rain, and the slope of the land
What happens when sediment eroded by water, ice, and wind slows down or stops moving?
It settles down and is deposited in a new location, a process called deposition.
How is water a weathering agent?
It dissolves minerals in rocks.
What type of physical weathering involves the peeling off of rock's layers?
Exfoliation
The grand canyon is an example of what type of erosion?
by water
In deserts, erosion by ________ can be the most important process that changes landforms.
Wind
rust formation (oxidation), limestone dissolving in rainwater (carbonation), feldspar in granite turning into clay (hydrolysis), the breakdown of rocks by acid rain, and the weathering of rocks by lichens which produce weak acids
What is the type of physical weathering that involves smoothing out matter?
Abrasion
Nonliving, solid material that are formed in nature and made of crystals.
Minerals
Where do erosion and deposition occur in a river?
Erosion occurs where fast-moving river water picks up soil and moves it downstream. Deposition occurs where a river current slows as it enters a larger body of water and drops the soil.
What are the two elements that cause oxidation?
Oxygen and hydrogen
Factors that cause mechanical weathering (at least 3 examples)
freezing and thawing of water in rock cracks, temperature fluctuations causing expansion and contraction, pressure release from the removal of overlying rock, plant root growth in cracks, animal burrowing, abrasion from windblown particles, and salt crystal formation within rock crevices
How might glaciers change a landscape over time?
carving valleys, sculpting mountains, and depositing large amounts of rock and sediment through a process called glacial erosion