MECHANICAL WEATHERING
When rocks are broken down into smaller pieces without changing their chemical composition
What is mechanical weathering?
when rocks are broken down and the chemical composition is changed
What is chemical weathering?
exfoliation, a gradual peeling of layers due to uplift and frost action
What is an example of mechanical weathering?
after a cold day, you notice that a rock's cracks are bigger than the day before
What is frost wedge, an example of the effects of water freezing repeatedly?
the area of an outer part or uppermost layer
What is surface area?
when water gets into cracks in rock, freezes, and expands
What is frost wedging?
oxygen in the air combines with iron to form rust
What is oxidation?
carbon dioxide combining with rain
What is an example of chemical weathering?
the sidewalk near a large tree is cracked
What is an example of the effects of plant growth?
Surface area
Rock composition (what it’s made of)
Climate
What are the three factors responsible for the rate of weathering?
grinding away rock by rock particles carried by wind water and gravity
What is abrasion?
chemicals in the air react with water vapor to form acids that combine with rain to break down rocks.
What is acid rain?
gravity causing landslides
What is an example of mechanical weathering?
a rock in a desert is worn away
What is an example of the effects of abrasion?
Tiny air spaces = more surface area = faster weathering
What is permeable?
causes landslides, sinkholes, etc. and is a constant pulling force to the ground
What is gravity?
some plants and similar creatures form weak acids that dissolve some rock
What are living organisms?
a mole digging
What is an example of animal actions (causing mechanical weathering)?
a statue outside is worn away as if it just melted
What is an example of the effects of acid rain?
Water, Waves, Wind, Glaciers, and Gravity
What are the 5 agents of weathering?
animals that burrow in the ground and break apart soil and rocks
What are animal actions?
mixes with rain and forms carbonic acid
What is carbon dioxide?
plant roots loosening, and breaking up rock
What is an example of root pry (action)?
limestone dissolved by carbonic acid
What is an example of the effects of chemical weathering?
repeated daily heating and cooling of rock; heat causes expansion; cooling causes contraction
What is thermal expansion?