L.O: weathering, erosion, deposition

When rocks are exposed to the environment, they can weather (break down).

Weathering when rocks breakdown into sediment (rock particles)

because they are exposed to the environment

Two kinds: physical and chemical weathering

Physical weathering rocks breakdown into sediment (small rock particles)caused by ice or biological activity

Chemical weathering: when the minerals in rocks dissolve or rust

from oxygen or acid rain

Chemical weathering happens in warm (hot) and humid (wet) environments.

Water is the greatest cause of weathering.

Small rocks weather faster than big rocks

Small rocks weather faster than big rocks

Rocks with soft minerals are less resistant to weathering

Rocks with harder minerals are more resistant to weathering

Soil is the result of the weathering of rocks and biological activity.

Erosion: when sediment (rock particles) are transported away.

Wind, gravity, ice (glaciers) and especially running water are agents

of erosion

Streams:

Streams (rivers) are moving water.

A stream’s velocity depends on its

• Gradient (slope)• Discharge (volume of water it carries)

The meander (outside of the bend) of a stream has the MOST erosion.

“C” has most erosion

Inside the bend (meander) has most deposition (“A”).

Which has more erosion? Which has more deposit?

Streams create V-shaped valleys

Streams create V-shaped valleys

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Glaciers are huge slow-moving “rivers of ice”.

Glaciers transport all sizes of rocks as they move.

Glaciers create U-shaped valleys.

Deposition:When agents of erosion deposit the

sediments they carry.

Deposition: When agents of erosion deposit the sediments they carry.

Streams deposit sediment with horizontal sorting.

• As a stream slows down: the Largest, heaviest, Roundest and densest particles are deposited first.

Glaciers deposit unsorted (mixed-up rocks) piles .