Download Chemical Weathering Foldable Rotations

Oxidation
Chemical Weathering – Oxidation
 Rocks with metallic elements combine with oxygen (in air and water)
and rust away (rust stains the rocks REDDISH BROWN).
 Oxygen combines with iron minerals and sulfur minerals, changing
the composition of the rock.
 These new substances are usually much softer and thus, easier for
other forces to break apart.
 Oxidation is responsible for the Statue of Liberty turning green.
Hydrolysis
Chemical Weathering – Hydrolysis
 Hydrolysis is the weathering reaction that occurs when water and
chemical compounds in a rock meet.
 This results in decomposition (the break-down) of the rock surface
by forming new compounds.
 The most common example of hydrolysis is feldspar, which can be
found in granite changing to clay.
Carbonation
Chemical Weathering – Carbonation
 Carbon dioxide (CO2) in the atmosphere dissolves in the droplets of
water that make-up clouds.
 This forms a weak carbonic acid.
 This is the same acid found in soda.
 This acid is too weak to harm plants and animals, but slowly causes
certain stones (i.e. feldspar and limestone) to decompose.
 The substances in rocks form new types of softer substances.
 Forms stalactites and stalagmites in caves as carbonic acid moves
through limestone.