Weathering The process of breaking down of rocks into smaller and smaller pieces of rock. These small pieces are known as sediment. Sediment breaks down further and becomes soil. YehliuTaiwan-HoneycombWeathering 180px-GeologicalExfoliationOfGraniteRock

 Mechanical/ Physical Weathering  Chemical Weathering Types of Weathering

 Ice Wedging- Water in the cracks of rocks freeze  Abrasion- Particles of sand are carried by the wind and water  Plant Action – roots from plants grow in the cracks of rocks  Release pressure – when pressure is removed from rocks Types of Mechanical Weathering

Chemical Weathering The process in which the chemical makeup of a rock is changed by a chemical reaction.

Types of Chemical Weathering  Oxidation – a chemical change that occurs when oxygen and iron form.  Acids – natural acids break down rock.

Erosion  Erosion takes rocks and other particles from one location and puts them in another.  Weathering is breaking up rocks erosion is carrying them away.

The Agents of Erosion  Wind  Water  Glaciers  Gravity / Mass Movement

Wind Erosion  Wind can carry sand, silt, and clay from one place and deposit it in another.  This type of erosion is most frequent in dry areas with little or no vegetation.

Wind Erosion

Water Erosion  The most important agent of erosion is running water.  Water runs down hill and form a gully by taking away sediment.  Water continues to flow in the gully and eventually forming a valley.  Water can cause erosion of the shore line can be from waves in the ocean.

Water Erosion

Water Erosion

Glaciers Erosion  Glacier Erosion is sometimes referred to as Ice Erosion  Glaciers move slowly across land picking up large rocks and even larger boulders.  Glaciers can cause deep valleys to form as they move across the land.

Glaciers Erosion

Gravity/Mass Movement Erosion  Gravity is the force behind Water and Glacier Erosion  Gravity alone can cause Erosion

Gravity/Mass Movement Erosion

 Slump  Creep  Rockfalls  Rockslides  Mudflows  Landslides Types of Gravity/Mass Movement Erosion

Slump  A slump occurs when a mass of land slips and moves down a slope.  A slump occurs when the slope becomes too steep and the material under it can not support the ground above it.

Creep  Sediment slowly moves down hill.  Leaning trees and fence post are clues that creeping is occurring

Rockfalls Occur when parts of a rock break off a tumble through the air.

Rockslides  Large and small rock slide down a slope.

Mudflows  Happen after heavy rains.  More likely to occur when there is a lack of vegetation.  Gravity pulls on the heavy water saturated sediment and causes it to flow down hill.

Landslides  A movement of land down a slope.

Deposition  Process by which sediments, soil and rocks are added to a landform or land mass (the end of erosion).