Flashcards
Unit 1.2 : Weathering
Flashcards do conjunto (20)
- 1What is the process of weathering?Weathering in geology means the breakdown of rocks by physical and chemical means.
- 2Why can't rocks last forever?Rocks do not last forever because weathering breaks them down into smaller pieces.
- 3What are the 5 reasons that cause Physical Weathering?Physical weathering can happen because of:
-Temperature Change
-Action of water and ice
-Crystallisation of salts
-Wind
-Living Plants
- 4How can temperature changes affect Physical Weathering?Solid expands when they are heated and contract when they are cooled. The expansion and contraction can crack a rock.
- 5How can ice and water split rocks?Ice can split rocks by cooling them rapidly, also it widens rocks. This is because any water that enters cracks will expand if it freezes
- 6What happens if crystals are formed within a rock?If the crystals form inside a rock, then the expanding crystals can put a tremendous pressure on the rock and can break pieces off it.
- 7What causes the rock surface to blast?Fine particles of rock carried by the wind can cause physical weathering. These fine rock particles blast the rock surface, wearing off pieces away.
- 8How can plant roots split rocks?Plant roots can split rocks by growing through fine cracks or even creating their own cracks. As the roots thickens, it splits the rock.
- 9What is chemical weathering?Chemical weathering involves water and chemicals in the water and air reacting with the rock and changing it.
- 10What are the agents of chemical wethering?Agents of chemical weathering are-:
-Gases
-Acids
-Water
- 11How are acids formed in chemical weathering?Rainwater contains dilute acids that attack the rock. The acids can naturally form in the air during lightning, but pollution also forms acids in the air. This is known as acid rain.
- 12What is the difference between erosion and weathering?Weathering is the breakdown of rocks by physical and chemical means, while Erosion is the removal of weathered rock particles away from the site of the weathering.
- 13What are the agents of Erosion?Agents of erosion are :-
-Water
-Wind
-Ice
- 14What is the process of Sedimentation or Deposition?The process of water or wind depositing eroded rock particles.
- 15What are the characteristics of soil that Plants depend on?Plant growth depends on several characteristics of the soil-:
-Texture
-Structure
-Water-holding capacity
-Permeability
-Consistency - 16TextureTexture is determined by the size of the particles that make up the soil. Soils are composed of particles of different sizes.
- 17StructureStructure refers to how well the soil particles join up to form soil clods or crumbs. Soil structure is about how particles clump together.
- 18Water-holding capacityWater-holding capacity is a measure of how much water a particular amount of soil can hold.Some soils hold onto water very strongly.
- 19PermeabililtyPermeability is a measure of how fast water enters the soil. If water enters the soil slowly and permeability is low, then the water is likely to run off and not enter the soil.
- 20ConsistencyConsistency is the tendency of soil particles to stick together.The soil forms a layer that sets like concrete, preventing water and air from entering.
