Weathering Flashcards
what is weathering
when rocks are worn away
when does chemical weathering occur
when rain water reacts with minerals in the rocks.
why is rain water slightly acidic
because it contains dissolved gases
when does physical weathering occur
the minerals in a rock expand if the rock get hot and contracts if it cools or If water gets into a crack in the rock and freezes. water expands when it turns to ice and makes the cracks wider.
what do changes in size cause
strong forces
what can make cracks in a rock
if the rock is heated and cooled over and over again the forces make cracks
what is onion skin weathering
when a rocks outer layer peels of due to extreme variations in temperatures
what is freeze-thaw action
when rocks get weathered by freezing and thawing of ice
what is biological weathering
when rocks are broken up or worn away by plants or animals
example of biological weathering
plant roots can grow into cracks in rocks and make the cracks bigger.
