Weathering, Erosion & Deposition Notes PDF

Weathering, Erosion and Deposition Notes  Weathering Weathering is the process in which materials on or near Earth’s surface break down and change. Mechanical weathering is a type of weathering in which rocks and minerals break down into smaller pieces. It does not change...

Weathering, Erosion and Deposition Notes  Weathering Weathering is the process in which materials on or near Earth’s surface break down and change. Mechanical weathering is a type of weathering in which rocks and minerals break down into smaller pieces. It does not change a rock’s composition. Chemical weathering is the process by which rocks and minerals undergo changes in their composition. Mechanical Weathering 01 Temperature 02 Pressure The freeze-thaw cycles of water in the when overlying rock layers are cracks of rocks is called frost removed by processes such as wedging. When the temperature erosion or even mining, the drops to the freezing point, water that pressure on the bedrock is is present in the cracks of rocks or reduced, increasing erosion. rock layers freezes, expands, and exerts pressure on the rocks. 03 Exfoliation 04 Topography The lay out and slope of the process in which outer rock land will determine the rate of layers are stripped away, often erosion resulting in dome-shaped formations. Chemical Weathering 01 Water 02 Oxygen can dissolve many kinds of The chemical reaction of minerals and rocks and serves oxygen with other as a medium in which substances is called oxidation chemical reactions can occur. 03 Carbon Dioxide 04 Acid Precipitation When carbon dioxide The slight acidity of the combines with water in the precipitation can cause it to atmosphere, it forms a very dissolve certain rocks, such as weak acid called carbonic limestone and marble. acid. Rates of Weathering CLIMATE The interaction between temperature and precipitation in a given climate determines the rate of weathering in a region. EX) Warm areas such as the tropics experience the fastest chemical weathering. Physical weathering can break down rocks more rapidly in cool climates. ROCK TYPE Not all the rocks in the same climate experience weathering at the same rate. SURFACE AREA Mechanical weathering breaks rocks into smaller pieces. As the pieces get smaller, their surface area increases, resulting in more total surface area available for chemical weathering. TOPOGRAPHY Steep slopes promote erosion and continually expose more rocks to weathering.  Erosion and Deposition Erosion is the process of removing weathered rock and soil from its original location Erosion can remove material through a number of different agents, including running water, glaciers, wind, ocean currents, waves, and gravity. Deposition is when the eroded rock and soil are are dropped in another location  Erosion Water Waves Glaciers Stream erosion can Carves out cliffs, arches, Glaciers have the ability reshape entire and other features along to erode vast amounts landscapes. a shoreline of material over a large area. Wind Gravity can easily pick up and the force of gravity tends to move fine, dry particles pull all materials downslope. Deposition Water Waves A river’s final destination is the ocean. Deposition of sand particles forms rivers deposit large amounts of sediment features such as beaches and near the region where they enter the sandbars ocean. Glaciers Wind soils across the midwest and the When wind moves large amounts of northern parts of the United States sand in dry areas, it creates dunes were formed from material that were deposited by glaciers.  Human Impact Humans move sediment when construction and other changes to the land are carried out. Human development and population growth along shorelines have led to attempts to control the erosion of sand. Efforts to keep the sand on one beachfront disrupt the natural migration of sand along the shore, depleting sand from another area.