Earth Science - Types of Weathering

Weathering

Breaking up of rock into smaller pieces from exposure to the atmosphere

Erosion

Removal and transport of weathered materials by natural agents (wind, water, ice, etc.)

Mass wasting

Downward transport of earth materials by gravity

Physical (Mechanical) Weathering

Breaks down WITHOUT changing composition, pieces still left over

Increase surface area

Chemical weathering

Dissolves, composition changes

Results mainly from interaction of water

Chemical weathering begins on the exterior surface of rock and works way inward

Frost Wedging

Physical Weathering

Water expands 10% when frozen

Will have tiny pieces left over

Water seeps in cracks: freezes, expand, breaks rocks apart

Root Action

Physical Weathering

Roots grow into cracks, rocks, expand and breaks rocks apart

Can be large roots from a tree or small glands of grass

Exfoliation

Physical Weathering

Flakes off in sheets

Uplift decreases pressure on rock (granite)

Abrasion

Physical Weathering

Worn down by friction

Rocks are large & angular when freshly broken

Sediments become smaller, rounder, smoother after carried in streams or the beating of small particles against a surface

Hydrolysis

Chemical Weathering

Dissolves minerals into ions

(Just dissolving)

Oxidation

Chemical Weathering

Rusting

Carbonation

Chemical Weathering

Acid Rain

Slowly dissolves anything with the mineral: calcite (such as limestone, marble)

Underground Caverns

Chemical Weathering

Carbonic Acid dissolves limestone (calcite) as it flows through cracks in the rocks

Limestone creates large ________ _______

Sinkholes

Chemical Weathering

Depressions in ground caused by collapse of cave roof

Rock dissolves underground: spaces & caves develop

Spaces grow larger = not enough support for land above

Plant Acids

Chemical Weathering

Moss or lichens have acid that breaks down rocks

Dissolves minerals of the rock, causing rock to deteriorate