Weathering erosion and deposition is evident everywhere we look – from sidewalk cracks to beaches filled with sand. These natural processes form part of the rock cycle which has been occurring for billions of years.
Forces such as water, wind, glaciers, and gravity all work to erode rocks into smaller fragments that can then be transported by erosion to new locations.
Mechanical Weathering
Mechanical weathering refers to the process of breaking rocks down into smaller particles without altering their chemical makeup, and is responsible for erosion, shaping landscapes over time, and turning tall mountains into rolling hills and plains. Wind, water, ice and gravity all play major roles in mechanical weathering; while rain water slamming against cliff faces grinds rocks into fine sediments while glaciers transport any size rock fragment from large boulders down to tiniest fragments while wind can carry away both types of fragments at great speed.
Temperature, pressure, frost action, roots and burrowing animals all play an essential part in mechanical weathering. Plant roots have the power to force their way into even tiny cracks in rocks to enlarge them as they grow; while mosses and lichen can break apart rocks that do not support root systems.
Chemical Weathering
Chemical weathering of rocks alters their internal mineral structures while altering their composition, releasing soluble minerals and fragments that can be carried away by rainwater and air currents. Chemical weathering often takes place in warm, moist climates where there is plenty of oxygen and water available for chemical reactions to occur.
Carbon dioxide in the air reacts with water to form a weak acid that dissolves limestone, producing caves such as those at Carlsbad Caverns in New Mexico, U.S.A. Chemical weathering breaks down its crystalline structure into more easily crumbled rock, while chemical weathering softens granite further by breaking down its crystal structure and producing soft rock layers that break off more readily than before.
Chemical weathering tends to alter minerals less drastically than mechanical weathering, yet still breaks down rocks that form soil. As more rock material is exposed to physical weathering processes resulting in increased erosion rates; later deposited lower elevations. Residual soils form on gentle slopes as these rocks break down and form loose aggregates composed of rock particles, clay minerals, metal oxides, and organic matter.
Biological Weathering
Biological weathering refers to the process by which living organisms break down rocks. Although it’s slower than its physical and chemical counterparts, biological weathering still has a vital impact on landforms and ecosystem health by contributing to soil formation.
Physical and chemical weathering processes do not alter rock composition significantly; however, plant roots and other living organisms can penetrate rock surfaces and expand into cracks of rocks to add pressure and aid other physical processes in breaking them down more rapidly.
Biological weathering also contributes to rock erosion by producing organic acids that decompose minerals found in rocks, creating mineral-rich soil which supports plant growth, biodiversity, and the Earth’s water cycle.
Human Activity
Physical and chemical processes which break down rocks and shape the land through physical or chemical actions, including erosion caused by trickle water trickling through Earth’s crust, are known as erosion processes. Gravity also plays a crucial role in moving material downward, potentially creating serious landslide risks.
Weathering and erosion can be found everywhere: from cracks in sidewalks to sand on beaches. Human activities can help or hinder this process of degeneration.
Weathering refers to the process of breaking down rock and minerals into smaller pieces. Erosion involves moving those weathered pieces, with deposition taking place when they land somewhere else. Erosion can be caused by wind, water, ice, plants and gravity; humans also add their part through mining, farming, construction and driving cars activities that contribute to erosion; air pollution is also an erosion driver by making rain acidic which damages limestone, marble and other forms of rock formations. Recycling resources more efficiently or employing alternative energy sources are great ways of helping reduce weathering and erosion rates significantly.