Weathering and Other Exogenic Processes

• ​external processes

• occur ​or or near the surface of the Earth

4Q Earth Science 12

• decomposition of rocks caused by chemical reactions resulting in formation of new compound

• caused by oxidation, hydrolysis, acid rain, carbonation​

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chemical weathering

• mechanical breakdown of rocks into smaller pieces

• ​caused by changes in temperature, pressure, frost/ice, water, wind, biological activity

physical weathering

Example of weathering:

The effect of frost wedging

Example of weathering:

The effect of changes in temperature

Example of weathering:

Can you figure out why the bases of the sea stacks are​ narrower than their bodies?

Example of weathering:

Effect of acid rain

Example of weathering:

How did karst rocks in Palawan form?

Example of weathering:

chemical weathering: oxidation

4Q Earth Science 12

• wind

• glaciers

• running water​

• waves

• gravity​

• others that will cause movement of weather rock and soil​

Agents of erosion

Examples of erosion:

Effects of wind and flowing water

Example of erosion: (Note: abrasion is a type of weathering)

Effects of glaciers

What is deposition?

4Q Earth Science 12

• The term ‘saltation’ describes the process by which sand grains are picked up and transported by the wind. Sand grains bounce along the ground in the wind; when the wind stops or slows down, the sand is deposited and may build sand dunes.

​​https://www.bgs.ac.uk/discovering-geology/geological-processes/deposition/

action of wind

​the laying down of sediment carried by wind, flowing water, the sea, or ice

Flowing water picks up and moves particles of soil and rock. When the water slows down, for example by reaching flatter land, it starts to drop the particles it is holding. It drops the largest particles first and the smaller ones as it slows down even further.​

​

​​https://www.bgs.ac.uk/discovering-geology/geological-processes/deposition/

action of water

​the laying down of sediment carried by wind, flowing water, the sea, or ice

Some text here about the topic of discussion

action of sea

​the laying down of sediment carried by wind, flowing water, the sea, or ice

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