Weathering is a process in which rocks get disintegrated into smaller particles or get decomposed at or near the surface of the Earth. For example, biological weathering. Denudation is a long term process in which the wearing and tearing of the surface of the Earth takes place.

Differences Between Weathering and Denudation Weathering is a short-term process, while denudation is a long-term process that takes years to occur. Weathering is caused by temperature changes, wind, rain, bacteria, and plants, whereas denudation is caused by volcanoes, earthquakes, and plate tectonics.

In geology, denudation is the long-term sum of processes that cause the wearing away of the Earth’s surface by moving water, ice, wind and waves, leading to a reduction in elevation and relief of landforms and landscapes.

Three regional types of denudation with a different directedness of relief-formation, controlled by the structure of climatic fluctuations, are considered.

Water is one of the four active agents of denudation (the others being wind, waves and glacial ice) that erode, transport and deposit sediments at the earth’s surface to produce erosional and depositional landform.

Denudation can involve the removal of both solid particles and dissolved material. These include sub-processes of cryofracture, insolation weathering, slaking, salt weathering, bioturbation and anthropogenic impacts.

Denudation and Erosion. Denudation includes all those processes that lower relief. It acts both chemically and physically. Chemical denudation is also called chemical weathering (Photo 4.3), and physical denudation is sometimes called mechanical weathering.

By measuring the concentration of nuclides in surface rocks, calculating a value for the nuclide production rate at the sampling site, and using known values for radioactive decay, a denudation rate can be determined.

Erosion is the geological process in which earthen materials are worn away and transported by natural forces such as wind or water.

Some of the most destructive examples of wind erosion are the dust storms that characterized the “Dust Bowl” of the 1930s in North America.

Surface erosion

• Sheet erosion. This occurs when rain falls on bare or sparsely covered soil, loosening fine particles (silt, clay and humus) that are carried downhill in surface run-off.
• Wind erosion.
• Rill erosion.
• Gully erosion.
• Tunnel gullying.
• Slips.
• Earth flows.
• Scree erosion.

Mechanical weathering (also called physical weathering) breaks rock into smaller pieces. These smaller pieces are just like the bigger rock, just smaller. That means the rock has changed physically without changing its composition.

Mechanical weathering, also called physical weathering, breaks rock into smaller pieces. These smaller pieces are just like the bigger rock, just smaller. That means the rock has changed physically without changing its composition.

Erosion happens when rocks and sediments are picked up and moved to another place by ice, water, wind or gravity. Mechanical weathering physically breaks up rock. One example is called frost action or frost shattering. Water gets into cracks and joints in bedrock.

Erosion is defined as the movement of rock by water or wind and is different from weathering, which requires no movement to occur.

• Mechanical Weathering and Abrasion. The most significant form of weathering is abrasion.
• Chemical Weathering and Disintegration.
• Weathering from Ice.
• Biological Weathering.

in the cracks and pores of rocks, the force of its expansion is strong enough to split the rocks apart. This process, which is called ice wedging, can break up huge boulders.

Physical Weathering Processes

• Abrasion: Abrasion is the process by which clasts are broken through direct collisions with other clasts.
• Frost Wedging:
• Biological Activity/Root Wedging:
• Salt Crystal Growth:
• Sheeting:
• Thermal Expansion:
• Works Cited.

These examples illustrate physical weathering:

• Swiftly moving water. Rapidly moving water can lift, for short periods of time, rocks from the stream bottom.
• Ice wedging. Ice wedging causes many rocks to break.
• Plant roots. Plant roots can grow in cracks.

There are two main types of physical weathering:

• Freeze-thaw occurs when water continually seeps into cracks, freezes and expands, eventually breaking the rock apart.
• Exfoliation occurs as cracks develop parallel to the land surface a consequence of the reduction in pressure during uplift and erosion.

There are two factors that play in weathering, viz. Temperature and Precipitation. Warm climates affect by chemical weathering while cold climates affect by physical weathering (particularly by frost action). In either case the weathering is more pronounced with more moisture content.

1.1. Physical weathering can occur due to temperature, pressure, frost, root action, and burrowing animals. For example, cracks exploited by physical weathering will increase the surface area exposed to chemical action, thus amplifying the rate of disintegration.

What Factors Determine the Rate of Weathering?

• Mineral Composition. One type of weathering, known as chemical weathering, works at different rates depending on the chemical composition of affected rocks.
• Type of Lattice.
• Temperature.
• Water and Salt.

Rainfall and temperature can affect the rate in which rocks weather. High temperatures and greater rainfall increase the rate of chemical weathering. 2. Rocks in tropical regions exposed to abundant rainfall and hot temperatures weather much faster than similar rocks residing in cold, dry regions.

Temperature changes can also contribute to mechanical weathering in a process called thermal stress. Changes in temperature cause rock to expand (with heat) and contract (with cold). As this happens over and over again, the structure of the rock weakens. Over time, it crumbles.