Weathering, erosion and deposition are natural processes that shape our landscape and form soil. When applied without consideration or consideration for environmental considerations, however, they can accelerate this process and strip our planet of its life-supportive qualities.
Weathering refers to the process of breaking down rocks and minerals into smaller components; erosion involves moving this material, while deposition occurs when it settles somewhere else; examples would be boulders in rivers or silt on land surfaces.
Weathering
Weathering, which occurs by physical and chemical processes on Earth’s surface, involves the breaking down of rocks and minerals onto its surface. These processes may occur separately or simultaneously and contribute to altering our rocky landscape over time.
Rocks exposed for extended periods are more susceptible to weathering. Different kinds of rocks also experience weathering at various rates; massive, solid rocks like granite may not experience planes of weakness while layered sedimentary rocks often do. Chemical weathering depends on both its mineral content and how readily it dissolves in water – for instance calcite dissolves much quicker in comparison to feldspar.
Mechanical weathering can be caused by various sources, including changes in temperature that cause rocks to expand and contract (swell and shrink) repeatedly, weakening its structure over time – this process is known as thermal stress and often seen in desert landscapes. When this process continues unchecked, layers may flake off in sheets – this process known as exfoliation may ensue.
Erosion
Water’s force is one of nature’s most potent tools for altering landscapes, from raindrops and floods from extreme weather, to ocean waves – can have dramatic results on landscapes. Rain, floods from extreme weather and ocean waves all play their part, eroding rocks, soil and sediments along their paths. Erosion may also be accelerated through chemical weathering (oxygen reacts with minerals in rocks to make them brittle) or physical processes such as rock fracturing or freeze-thawing processes.
Water erosion can be caused by wind or ice. The amount of erosion depends on environmental factors like rainfall and wind speed, with rapid flows leading to even faster erosion rates.
Fast-moving water has an enhanced capacity to erode rock and soil more than slower-moving waters do, creating canyons like Arizona’s Grand Canyon as well as landscape features like Canada’s Baffin Island waterfall. Eroded sediments contribute to creating rich delta soils of rivers worldwide while physical erosion forms features like gullies, canyons and cliffs on Earth’s surface.
Deposition
Weathering and erosion are natural processes that have helped shape our planet’s landscape, altering it over time by depositing sedimentary rock layers as they erode away. Deposition occurs daily on beaches when ocean waves strike rocks to wear away at their surfaces, leaving behind deposits of sand that eventually form bars, spits, and bayhead beaches.
Water is one of the primary agents for both mechanical and chemical weathering processes (fracturing) as well as physical weathering (freezing, thawing, pressure changes, pressure from underground sources or burrowing animals). Temperature changes, freezing/thawing cycles, pressure fluctuations or burrowing animals may also play a part.
Chemical weathering occurs when acidic rainwater percolates through and dissolves minerals and rocks on or under the surface of Earth, dissolving them in ways similar to carbonic acid-infused rainwater eroding limestone cave systems such as those at Carlsbad Caverns National Park in New Mexico.
Root Throw
Since Earth began, weathering and erosion have played an ever-important role in shaping its landscape. Weathering breaks down rock surfaces into smaller pieces while erosion transports these fragments elsewhere – driven by wind, water, ice, plants, gravity changes in temperature or changes.
Rain is one of the primary means by which rocks and soil deteriorate over time, quickly filling any cracks or gaps in rocks; but as temperatures drop, its liquid state freezes into solid form – expanding and widening cracks while potentially splitting rocks in the process.
Plant roots can cause mechanical weathering as well. When growing plants wedge into cracks between rocks and expand them slowly over time – known as sheeting or exfoliation – their roots will gradually wedge between cracks to enlarge them and produce fragments of rock that often form well-sorted structures; but erosion still often carries away some particles; this process may occur rapidly like during mudslides, slowly like glaciers or even underground like limestone caves.