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Weathering, Erosion, and Deposition. How are weathering and soil formation related? How do weathering, erosion, and deposition change Earth ’ s surface? How are erosion and deposition related?. Lesson 3 Reading Guide - KC. Weathering, Erosion, and Deposition. weathering erosion
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Weathering, Erosion, and Deposition • How are weathering and soil formation related? • How do weathering, erosion, and deposition change Earth’s surface? • How are erosion and deposition related? Lesson 3 Reading Guide - KC
Weathering, Erosion, and Deposition • weathering • erosion • physical weathering • chemical weathering • soil • sediment • deposition Lesson 3 Reading Guide - Vocab
Weathering • Weathering refers to the processes that break down rocks, changing Earth’s surface over time. • Erosion is the moving of weathered material, or sediment, from one location to another. Lesson 3-1
Weathering (cont.) Slowly but surely, weathering and erosion wear down mountains. Photo by Tim McCabe, USDA Natural Resources Conservation Service Dr. Parvinder Sethi Lesson 3-1
Weathering (cont.) • The process of breaking rock into small pieces without changing the composition of the rock is physical weathering. • Frost wedging is what occurs when water in rocks freezes and melts repeatedly, breaking the rocks apart. Lesson 3-1
Weathering (cont.) The roots of plants can grow into cracks in rock and eventually break the rock. Lesson 3-1
Weathering (cont.) • The process of changing the composition of rock and minerals by exposure to water and the atmosphere is called chemical weathering. • Gases in the atmosphere can cause chemical weathering. Lesson 3-1
Weathering (cont.) • Physical weathering exposes more surface area of rocks, allowing more water and atmospheric gases to enter rocks. • Chemical weathering weakens rocks by changing the composition of some minerals and dissolving others. Lesson 3-1
Weathering (cont.) • Soil consists of weathered rock, mineral material, water, air, and organic matter from the remains of organisms. • Soil forms directly on top of the rock layers from which it is made and is the result of hundreds to thousands of years of weathering. Lesson 3-1
Soil formation begins when physical and chemical weathering break down rocks. Lesson 3-1
Soil formation begins when physical and chemical weathering break down rocks. Lesson 3-1
Weathering (cont.) • Warm, wet climates produce soil fastest. • Large amounts of rain can speed weathering of rocks, and chemical reactions are faster in warmer temperatures. Lesson 3-1
Erosion • The minerals and small pieces of rock produced by weathering are called sediment. • Moving water causes erosion by picking up rock pieces and sediment, which scrape along the ground picking up more material. Lesson 3-2
Large masses of ice, called glaciers, cause erosion by flowing down a mountain and removing rock and sediment. • Erosion by glaciers makes deep valleys and steep peaks. Lesson 3-2
Strong winds also can erode and move sediment. • Soil and rock that are not protected by plants can be eroded by wind. U.S. Department of Agriculture Lesson 3-2
Deposition • Deposition is the process of laying down eroded material in a new location. • If the speed of flowing water decreases, the water can no longer carry sediment and the sediment settles at the bottom of the water. • Floodplains form when sediment settles out of rivers that flood the areas next to them. Lesson 3-3
When glaciers melt, the water produced by the melting ice does not flow fast enough to carry sediment. • Glacial deposits of sediment are called moraines. Lesson 3-3
Wind also can deposit sediment. • Sand dunes are landforms made as wind continually moves and deposits sand grains. Tim McCabe/NRCS Lesson 3-3
Deposition(cont.) • The locations where sediment accumulates are called sedimentary basins. • Sediment continues to be deposited in low areas and then forced upward as tectonic activity forms mountains. Lesson 3-4
Physical and chemical weathering work together and change Earth’s surface. They break down rock and form sediment. • Erosion occurs when sediment is removed and transported from where it formed. • Deposition occurs when sediment is laid down in new locations. Lesson 3 - VS
Which process breaks rock into small pieces without changing the composition of the rock? A. deposition B. erosion C. chemical weathering D. physical weathering Lesson 3 – LR1
Which are the minerals and small pieces of rock produced by weathering? A. glaciers B. sand dunes C. sediment D.soil Lesson 3 – LR2
Which location accumulates sediment? A.soil B.glacier C.sand dune D.sedimentary basin Lesson 3 – LR3
Do you agree or disagree? 5. Rocks cannot change. 6. Sediment can be transported by water, wind, and ice. Lesson 3 - Now