Studied by 5 people
Looks like no one added any tags here yet for you.
Weathering and Erosion
examples of exogenic processes that occurs on the surface of the Earth.
Weathering
process of breakdown of rocks to smaller bits.
“How rocks disintegrates?”
chemical and physical breakdown of rocks
Erosion
movement of Earth materials from one place to another.
Mechanical and Chemical Weathering
Two classifications of Weathering
Mechanical Weathering
alteration of rocks in terms of their size, shape and appearance without changing their chemical composition.
Frost Wedging
expansion of water as it freezes between the cracks in the rocks.
Thermal Expansion & Contraction
repeated heating and cooling of materials cause rigid substances to crack and separate.
Exfoliation
as the underlying rock is exposed, there is less pressure on them and they expand, causing the rigid layers to cracked.
often form a dome.
Abrasion
moving sediments or rock sections can break off pieces from a rock surface they strike.
Wind and Water
Two agents of Abrasion
Wind
agent of abrasion which carries blown away tiny bits of minerals and causes abrasion to the rocks
Water
an agent of abrasion that is cause by the impact of waves, tides and current that breaks the rocks.
Plant Growth/Wedging
the roots of plants and animals seeks space for them to grow causing the rocks to weather.
Chemical Weathering
processes that change the chemical composition of rocks.
Dissolving (Dissolution)
Prescence of solvent (commonly water) and solute such as acid that dissolves minerals from a rock body.
Acidic Rain
strong to calcites
Carbonic Acid
easily weathers marble and limestone
Oxidation
water + oxygen + iron = RUST
ex. Pyrite to Limonite
Hydrolysis
= means water, = to breakdown
minerals may combine with water to form new mineral.
ex. Feldspar to Kaolinite
Climate
Plants & Animals
Time
Mineral Compostion
Factors of Chemical Weathering
Climate
wet and warm maximizes chemical reactions
Plants/Animals
living organism secrete substances that react with rock.
Time
longer contact means greater change
Mineral Composition
some minerals are more susceptible to change than others.
