Weathering, Erosion, And Deposition
Weathering, erosion and deposition are mechanical processes that result in the wearing of, movement and sedimentation of earth materials such as rocks, soil, sand and remains of plants and animals. Physical and chemical processes result in the breakdown of rocks and dirt into small particles that are easy to move around. The results of weathering, erosion, and deposition can be beneficial or harmful to human beings, plants and animals. However, the processes are always beyond social control and occur naturally. Weathering, erosion and deposition could be a slow process occurring over a thousand to billions of years, but eventually, the results are remarkable. The results could force humans and animals to relocate, while others could lead to the formation of attractive natural features.
Weathering refers to the dissolving of rocks, soil and minerals on the surface of the earth by water, ice, acids, salts, animals and temperature changes. The process occurs in one place with little or no movement of residues. Weathering can either be chemical or physical. Mechanical weathering involves the continuous dissolution of rocks and soil through contact with conditions of the atmosphere such as animals, plants, exfoliation, heat, water, ice, salt and pressure. On the other hand, chemical weathering involves changes in the molecular structure of rocks and soil. The primary causes of chemical weathering include oxidation, hydrolysis, carbonation, hydration and living organisms. For instance, the combination of carbon dioxide produces carbonic acid, which dissolves limestone, causing the formation of caves. The Carlsbad Caverns National Park in New Mexico has over 119 limestone caves from weathering and subsequent erosion.
Erosion is the removal of earth materials such as rock and soil debris and their transportation from one point to another by natural factors such as water or wind. In most cases, erosion involves the physical movement of rocks, which does not affect the chemical composition. Mechanical erosion results in clastic sediments comprising of older rocks from a different place. Mass wasting results in the movement of stones from one place to another. Rainfall water results into different types of erosion including splash, sheet, rill, gulley and valley erosions. The Fish River Canyon in Namibia is a product of valley erosion. Corrosion has a massive impact on human settlements. For instance, coastal erosion nearly broke down The Cape Hatteras Lighthouse in the coast of North Carolina in the US. On the other hand, the erosion of ice glaciers in the Nothern Hemisphere resulted in the formation of the Finger Lakes in New York.
Deposition refers to the movement of materials through weathering and erosion and their sedimentation in one place. Sedimenting materials involves rocks, minerals, plant remains and animals and sand, which eventually form patterns the result to occurrence of physical features. Water can wash away small stones and sediments and accumulate them at the deltas, water banks and the feet of waterfalls. Also, glaciers can sediment erosion materials which eventually move downstream as ice. Sediments enrich the soil with nutrients creating a healthy environment for plants and animals. For instance, the banks of the River Nile in Egypt is the most fertile land in the country. In a few cases, layers of sediment can deposit, leading to the formation of sedimentary rocks. Also, when evaporation occurs, it results in the creation of ocean salt such as the Bonneville Salt Flats in Utah. The sedimentation of plant and animal materials at the bottom of the oceans leads to the formation of coal available in all continents globally except Antarctica.