Physical Weathering
The flow of water is the __________ agent of physical weathering
strongest/greatest
The process that occurs when oxygen reacts with iron-rich minerals in rocks.
Oxidation
What do rivers form when they deposit sediment at the mouth?
a river delta
What is rate?
How fast or slow something goes
What do we call dead plant and animal matter in soil?
humus
___________ happens when water fills in cracks in a rock and then freezes, expanding and eventually cracking the rock.
Ice-wedging
Burning of fossil fuels creates what type of percipitation?
Acid rain
What do streams form when emptied onto a flat plain at the foot of a mountain? Is this constructive or destructive?
alluvial fan, constructive
What increases weathering by breaking rocks into smaller pieces?
cracks or breaks
What layer of soil contains the most nutrients?
How do plants contribute to weathering?
Their roots expand, breaking rocks
What happens to iron when it gets wet and reacts with air? (not oxidation, but...)
rust
A ___________ is a u-shaped valley formed by glacial erosion.
cirque
What type of weathering happens faster in rainy places?
chemical
What type of soil holds the most water?
clay
What type of weathering is caused by wind-blown sand scraping rock surfaces?
abrasion
What type of climate speeds up chemical weathering-hot and wet or cold and dry
hot and wet
The agents of erosion are....
wind, moving water, glaciers, and gravity
What living things can speed up both types of weathering?
plants and humans
The removal from soil of substances that can be dissolved in water is called...
leaching
What type of animal activity can cause physical weathering?
burrowing
What green and gray organisms grows on rocks and makes weak acids?
lichen
Hoodoos are created by (constructive or destructive) erosion.
destructive
Which weathers faster, limestone or granite?
limestone
What horizon collects the dissolved nutrients that have been leached from above?
B-subsoil