Copy the definition below from the geological society.
Weathering is the breakdown of rocks at the Earth’s surface, by the action of rainwater, extremes of temperature, and biological activity. It does not involve the removal of rock material.
Weathering is a fundamental Earth process. Weathering changes rocks from a hard state, to become much softer and weaker, making them more easily eroded.
There are three types of weathering, physical, chemical and biological.
Weathering is the breakdown of rocks at the Earth’s surface, by the action of rainwater, extremes of temperature, and biological activity. It does not involve the removal of rock material.
Weathering is a fundamental Earth process. Weathering changes rocks from a hard state, to become much softer and weaker, making them more easily eroded.
There are three types of weathering, physical, chemical and biological.
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How is erosion different to weathering?
Erosion is the process by which soil and rock particles are worn away and moved elsewhere by wind, water or ice. Weathering involves no moving agent of transport.
Why is weathering important?
Perhaps the most important aspect of weathering is its role in the formation of soil. Without soil, life as we know it on earth would not exist. Soil is a much overlooked element of earth's processes and, at current rates of human use and abuse, is becoming a finite resource.
Task
Watch the video below from the Food and Agriculture Organisation of the United Nations and make notes on the most important points raised.
Watch the video below from the Food and Agriculture Organisation of the United Nations and make notes on the most important points raised.
Other important processes are shown in the images below.
Task
For each image, explain how weathering might impact upon the situation or activity shown.
Task
For each image, explain how weathering might impact upon the situation or activity shown.
Physical (mechanical) weathering
Physical weathering is also referred to as mechanical weathering. It is the weakening of rocks followed by disintegration due to the physical or mechanical forces including the actions on the rocks by abrasion, frost chattering, temperature fluctuations and salt crystal growth.
External environmental forces such as wind, water waves, and rain also consistently exert pressure on the rock structures resulting in accelerated disintegration. Physical weathering does not involve any chemical changes because the chemical composition of the rocks is never altered.
External environmental forces such as wind, water waves, and rain also consistently exert pressure on the rock structures resulting in accelerated disintegration. Physical weathering does not involve any chemical changes because the chemical composition of the rocks is never altered.
Task
Watch the video and make bullet points on the content.
1. Which climates experience the strongest rates of weathering?
2. Explain why this is.
Watch the video and make bullet points on the content.
1. Which climates experience the strongest rates of weathering?
2. Explain why this is.
3. Watch the animation by clicking the link opposite.
Explain the process of freeze thaw in your own words using key terms and geographical terminology. |
Chemical weathering
This is the decomposition of rocks due to chemical reactions occurring between the minerals in rocks and the environment. The examples below illustrate chemical weathering.
Water Water, and many chemical compounds found in water, is the main agent of chemical weathering. Feldspar, one of the most abundant rock-forming minerals, chemically reacts with water and water-soluble compounds to form clay. Acids Water contains many weak acids such as carbonic acid. This weak, but abundant, acid is formed when carbon dioxide gas from the atmosphere mixes with rainwater. Sulfur dioxide and nitrogen gases create other types of acid rain that act as chemical weathering agents. Some sources of sulfur dioxide are power plants that burn coal; as well as volcanoes and coastal marshes. Sulfur gases react with oxygen and rainwater to form sulfuric acid. Although relatively weak, acid’s abundance and long term effects produce noticeable damage to vegetation, fabrics, paints and rocks. Oxidation Oxidation is another kind of chemical weathering that occurs when oxygen combines with another substance and creates compounds called oxides. Rust, for example, is iron oxide. When rocks, particularly those with iron in them, are exposed to air and water, the iron undergoes oxidation, which can weaken the rocks and make them crumble. |
Task
Create a concept map like the one opposite that summarises the key ideas and relationships for the 3 chemical weathering examples above. Label each diagram clearly and add some extra detail to the key concepts and words used. Describe each concept as briefly as possible; usually one or two words per idea will suffice. Keeping your descriptions concise will prevent your map from becoming bloated and text-heavy. |
Biological weathering
Weathering review
Task
Watch the video below as a final review. Use it and your previous notes and knowledge to create a 6 question Kahoot for use as peer assessment with the rest of the class.
Watch the video below as a final review. Use it and your previous notes and knowledge to create a 6 question Kahoot for use as peer assessment with the rest of the class.
Impacts and processes of weathering and erosion
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TASK - Formative assessment
Create an infographic that highlights the importance of the weathering and erosion processes upon landscapes, ecosystems and human society.
This is a large topic area, so you may chose to narrow the focus to one particular process or impact, such as soil. Whatever you choose, include these elements:
Follow the guidance and instructions below to create your infographic.
Here's how to do an infographic!! And below the slideshow, a link to a website that shows you how to do infographics using PowerPoint.
Create an infographic that highlights the importance of the weathering and erosion processes upon landscapes, ecosystems and human society.
This is a large topic area, so you may chose to narrow the focus to one particular process or impact, such as soil. Whatever you choose, include these elements:
- Data
- Maps
- Locations
- Political
- Economic
- Social
- Environmental
Follow the guidance and instructions below to create your infographic.
Here's how to do an infographic!! And below the slideshow, a link to a website that shows you how to do infographics using PowerPoint.
Sign up and access free templates below.
Other options here.