WEATHERING and SOIL

Weathering

The process that involves the physical and chemical breakdown of materials on Earth’s surface.

Mechanical Weathering

Occurs when a physical change takes place; rocks are broken down into smaller pieces without changing their chemical composition.

Frost Wedging

A type of mechanical weathering where water collects in the cracks of a rock, freezes, expands, and forces the cracks apart.

Chemical Weathering

Involves chemical changes that cause the breakdown of rocks; caused by reactions between rocks and water, oxygen or acids.

Oxidation

A chemical reaction that occurs when iron-rich rocks are exposed to oxygen in water or air, forming rust.

Hydrolysis

A chemical reaction where feldspar reacts with water to form clay minerals, which help store water and absorb nutrients.

Soil

A mixture of weathered rock, organic matter, water, and air capable of supporting plant life.

Parent Material

The material from which soil forms, which can be either residual (weathered in place) or transported (brought from another location).

Erosion

The process that wears down and carries away rock and soil, acting through weathering, gravity, and movement by streams, glaciers, wind, and waves.

Delta

A fan-shaped sediment deposit that forms at the mouth of a river.

Mass Wasting

The movement of material down a slope under the influence of gravity, often occurring on steep, vegetated slopes.