Flashcards

Weathering

Zahraa Al Awadi English 20 cards

Cards in this deck (20)

1What is weathering?Weathering is the physical and chemical processes that break down rocks into smaller pieces.
2Do rocks last forever?No they don't, because they are broken down by weathering.
3What are the physical means of weathering?The physical means of weathering are temperature change, action of water and ice, crystallisation of salts, wind and living plants.
4How does temperature change affect rocks?Solids expand when they are heated but contract when cooled. Expansion and contraction can crack a rock if temperature changes between day and night.
5How does ice and water affect rocks?Ice can split rocks by cooling them rapidly. It can also widen the cracks in rocks.
6How can the crystallisation of salts affect rocks?Salts such as sodium chloride and calcium sulfate form crystals as water evaporates. If these crystals form within a rock, then the expanding crystals can put so much pressure on the rock from the inside, breaking pieces of it off.
7How does wind affect rocks?Rock particles blown away by the wind can blast the rock surface, wearing piece by piece away.
8How do plants affect rocks?Plants affect rocks by growing their roots through fine cracks in the rock, resulting in the rock being split.
9What is chemical weathering?Chemical weathering is the water or chemicals in the water that react with the air and break down the rocks.
10What are the chemical means of weathering?The chemical means of weathering are gases, acids and water.
11What does sedimentation mean?Sedimentation is the pieces of water or wind depositing eroded rock particles.
12What does erosion mean?Erosion is the removal of weathered rock particles away from the site of weathering.
13What are the agents of erosion?The agents of erosion are wind, water and ice.
14What is permeability?Permeability is a measure of how fast water enters the soil.
15What is the water-holding capacity?The water-holding capacity is a measure of how much water a particular amount of soil can hold.
16What is consistency?Consistency is the tendency of soil particles to stick together.
17What are the other components found in soil?The other components, other than sediments, found in soil are living organisms (such as bacteria or fungi), decaying wastes, dead leaves, twigs and insects, water, dissolved minerals and gases.
18What is the soil texture?The soil texture is determined by the size of the particles that make up the soil. Texture can affect plant growth by its effect on plant nutrients in the soil.
19What is the soil structure?The soil structure is determined by how well the soil particles join up to form lumps. The size of these lumps is important because it creates pore spaces to exist between the crumbs, allowing air and water to flow through. They should be 3-5 millimetres wide in most soils.
20How is soil used in farming, mine rehabilitation and market gardening?Soils are compacted by wheels and form a layer like concrete to prevent air and water from entering.