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Weathering,Erosion and Deposition. Science Grade 7. Weathering. Is the breaking of rock into smaller and smaller pieces. Plants: the roots get into the cracks and make the cracks larger as it grows. Mechanical Weathering. Rocks broken down by a physical process
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Weathering,Erosion and Deposition Science Grade 7
Weathering Is the breaking of rock into smaller and smaller pieces
Plants: the roots get into the cracks and make the cracks larger as it grows MechanicalWeathering Rocks broken down by a physical process Chemical make up of the rock stays the same Animals: dig and burrow making cracks bigger Ice Wedging: water gets into the cracks, freezes and expands the crack
Natural Acids: water mixes with carbon dioxide and makes carbonic acid which makes calcite dissolve Chemical Weathering Rocks are changed into different minerals Plant Acids: roots and decaying plants give off acids that dissolve rocks Oxidation: metal exposed to oxygen and water for a long time, forms rust
Soil is moved from one place to another Erosion Agriculture – plowing loosens the soil Forest harvesting – removes the roots that hold soil in place Over grazing of animals – they eat the plants that hold the soil down Urban construction – removal of trees and plants that hold soil Gravity, Wind and Water Glaciers
Deposition The state of being deposited