weathering Flashcards
weathering definition (1)
breaking down or disintegration of substances like rocks or statues
types of weathering (3)
- physical
- biological
- chemical
physical/mechanical weathering (2)
breaking down rocks w/o change in chemical composition
-caused mainly by temp and water
types of physical weathering (2)
- freeze thaw
- thermal stress/fracturing
freeze thaw (2)
- happens when theres cycles of cold and hot weather
- water gets into cracks of rock and expand when frozen
thermal stress (1)
-expansion and contraction of rocks due to heat
types of thermal stress/fracturing (2)
- exfoliation
- granular disintegration
exfoliation (1)
when outside of rock heats up but contracts at night causing thin layer of rocks to peel off
granular disintegration (1)
particles of rocks expand and contract at different rates, creating cracks and then small grains/particles falling off
types of chemical weathering (2)
- oxidation
- carbonation
chemical weathering (2)
- breaking down of rock due to change in chemical composition
- common in warm moist areas
oxidation (2)
-when oxygen mixes with minerals in rock to form oxides
-crumbles and weakens rocks
[eg rust, uluru]
carbonation (1)
dissolving of rocks from acidic water
[commonly occurs in limestone and chalk]
hyrdrolysis (1)
silicates in rocks mix with water, which turns into clay, which can be washed out easily and crumble apart
biological weathering (1)
weathering due to living organisms
[eg plant roots, burrowing animals, lichen {releases acidic stuff to dissolve rocks}]
