Weathering and Erosion Amole Spectra of Science 2013

Weathering vs. Erosion They work together, but are NOT the same thing Weathering is like the hammer. They work together, but are NOT the same thing Weathering is a process that breaks down rock Erosion is a process that moves rock Erosion is like the truck.

Types of Weathering Physical- breaks down rock without changing its chemical composition Frost wedging Plant roots Wind Water Chemical-breaks down rock by changing its chemical composition CO2 Acid Precipitation Rust

Frost Wedging Physical Weathering Water seeps into cracks Freezes and expands Pushes rock apart

Root Pry Physical Weathering Plant roots grow into rock Pushes rock apart

Wind Abrasion Physical Weathering Wind carrying sand blasts against these rocks causing them to become rounded

Animal Burrows Physical Weathering Animals create tunnels in rock and sediments breaking them up

Water Abrasion Physical Weathering Running water repeatedly flows over river rocks making them smooth

Oxidation of Iron Chemical Weathering This rock is red because of the oxidation of iron in the sediment when the rock was being formed

Acid Precipitation 1908 1969 Chemical Weathering Released gases from burning fossil fuels react with water in the air to create acids This acid reacts with limestone to decompose it 1908 1969

Living Organisms Lichens that grow on rocks produce weak acids that chemically weather rock

Water Chemical Weathering Water can dissolve minerals found in rocks

Water Chemical Weathering Water can dissolve minerals found in rocks

Carbon Dioxide Chemical Weathering Reacts with water to form acid

Erosion Process by which rock is moved or transported Deposition- process by which material (sediments) are laid down

Water Erosion Water transports and then eventually deposits sediments Can create deltas, meanders, canyons, and flood plains

Meander S-shaped streams Wander side to side seeking lowest elevation

Delta Occur where rivers meet the ocean Soil, dirt, sediments deposited at river mouth Creates new soil-rich land

Canyons Large valleys created by rivers or streams over time Grand Canyon “cut” by Colorado River

Wind Erosion Wind picks up and carries sediments to new locations Creates sand dunes

Erosion by Gravity Gravity causes large masses off rocks and sediments to move from higher locations to lower ones Ex: avalanches, land slides, and mudslides

Erosion by Ice Glaciers carve U-shaped valleys as they pick up and carry rock fragments along the way

Weathering and Erosion QUIZ

Frost Wedging Physical Weathering

Chemical weathering Rust

Root Pry Physical Weathering

Water Erosion

Erosion by Glacier

Erosion by Gravity

Erosion by Gravity

Physical Weathering- Frost Wedging Erosion- Wind

Chemical Weathering- Acid Precipitation The marble grave marker has been attacked by acidic rain because of the calcite composition. The grave marker on the right, while old, has not been dissolved because of its granite composition

Physical Weathering-Tree Pry Erosion by Gravity