weathering

Weathering defines the breaking down or dissolving of rocks and also minerals ~ above the surface of the Earth. Water, ice, acids, salts, plants, animals, and changes in temperature are all agents that weathering.

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Weathering describes the breaking down or dissolving of rocks and minerals on the surface of the Earth. Water, ice, acids, salts, plants, animals, and changes in temperature are all agents of weathering.
Once a rock has actually been damaged down, a process called erosion transports the bits that rock and also mineral away. No absent on earth is hard enough to resist the pressures of weathering and also erosion. Together, this processes sculpted landmarks such as the cool Canyon, in the U.S. State that Arizona. This substantial canyon is 446 kilometers (277 miles) long, as lot as 29 kilometers (18 miles) wide, and also 1,600 meter (1 mile) deep.
Weathering and also erosion constantly readjust the rocky see of Earth. Weathering wears far exposed surfaces end time. The size of exposure frequently contributes to how fragile a absent is come weathering. Rocks, such together lavas, that space quickly hidden beneath other rocks room less breakable to weathering and also erosion than rocks that room exposed to agents such as wind and also water.
As the smoothes rough, sharp rock surfaces, weathering is frequently the very first step in the production of soils. Tiny bits of weathering minerals mix with plants, pet remains, fungi, bacteria, and other organisms. A single form of weathering rock often produces infertile soil, when weathered materials from a repertoire of rocks is richer in mineral diversity and contributes to much more fertile soil. Soils species associated v a mixture of weathering rock encompass glacial till, loess, and also alluvial sediments.
Weathering is often split into the procedures of mechanically weathering and also chemical weathering. Organic weathering, in which living or once-living organisms add to weathering, deserve to be a part of both processes.
Water, in either fluid or hard form, is regularly a an essential agent of mechanically weathering. Because that instance, liquid water have the right to seep into cracks and also crevices in rock. If temperatures drop short enough, the water will certainly freeze. Once water freezes, that expands. The ice cream then works as a wedge. It slowly widens the cracks and splits the rock. As soon as ice melts, fluid water performs the action of erosion by carrying away the small rock pieces lost in the split. This specific procedure (the freeze-thaw cycle) is called frost weathering or cryofracturing.
Temperature changes can likewise contribute to mechanical weathering in a process called heat stress. Transforms in temperature reason rock to broaden (with heat) and also contract (with cold). As this happens over and over again, the framework of the rock weakens. Over time, the crumbles. Rocky desert landscapes are specifically vulnerable to heat stress. The external layer that desert rocks undergo repetitive stress together the temperature alters from day come night. Eventually, external layers flake off in thin sheets, a procedure called exfoliation.
Exfoliation contributes come the development ofbornhardts, among the most dramatic features in landscapes developed by weathering and also erosion. Bornhardts room tall, domed, isolated rocks often uncovered in dry areas. Sugarloaf Mountain, an iconic landmark in Rio de Janeiro, Brazil, is a bornhardt.
Changes in push can likewise contribute come exfoliation as result of weathering. In a procedure called unloading, overlying products are removed. The underlying rocks, exit from overlying pressure, have the right to then expand. As the rock surface ar expands, that becomes fragile to fracturing in a process called sheeting.
Another kind of mechanically weathering occurs once clay or other products near absent absorb water. Clay, an ext porous 보다 rock, have the right to swell with water, weathering the surrounding, harder rock.
Salt likewise works to weather rock in a procedure called haloclasty. Saltwater occasionally gets into the cracks and pores that rock. If the saltwater evaporates, salt crystals room left behind. Together the crystals grow, castle put push on the rock, gradually breaking the apart.
Honeycomb weathering is associated with haloclasty. As its surname implies, honeycomb weathering describes rock formations through hundreds or even thousands that pits developed by the development of salt crystals. Honeycomb weathering is common in coastal areas, whereby sea sprays constantly force rocks to interact with salts.
Haloclasty is not restricted to coastal landscapes. Salt upwelling, the geologic process in which underground salt domes expand, can contribute to weathering of the overlying rock. Frameworks in the old city the Petra, Jordan, were made unstable and also often broke down due to salt upwelling from the ground below.
Plants and animals deserve to be agents of mechanical weathering. The seeds of a tree may sprout in soil the has gathered in a cracked rock. Together the roots grow, castle widen the cracks, ultimately breaking the rock into pieces. End time, trees can break personal even big rocks. Even small plants, such together mosses, deserve to enlarge tiny cracks together they grow.
Animals the tunnel underground, such together moles and prairie dogs, additionally work to rest apart rock and soil. Other animals dig and also trample rock aboveground, causing rock to gradually crumble.
For instance, carbon dioxide native the waiting or soil periodically combines through water in a procedure called carbonation. This produce a weak acid, called carbonic acid, that can dissolve rock. Carbonic acid is especially reliable at dissolve limestone. When carbonic acid seeps with limestone underground, it can open up large cracks or hollow out vast networks that caves.
Carlsbad Caverns national Park, in the U.S. State of brand-new Mexico, includes much more than 119 limestone caves produced by weathering and also erosion. The biggest is referred to as the big Room. With an area of about 33,210 square meters (357,469 square feet), the big Room is the dimension of 6 football fields.
Sometimes, chemistry weathering dissolves huge portions of limestone or various other rock on the surface of the planet to form a landscape dubbed karst. In this areas, the surface rock is pockmarked with holes, sinkholes, and also caves. One of the world’s many spectacular examples of karst is Shilin, or the rock Forest, close to Kunming, China. Thousands of slender, sharp towers of weathering limestone increase from the landscape.
Another form of chemistry weathering functions on rocks that contain iron. These rocks turn to rust in a procedure called oxidation. Rust is a compound produced by the communication of oxygen and also iron in the existence of water. As rust expands, that weakens rock and also helps break it apart.
Hydration is a kind of chemistry weathering in i m sorry the chemistry bonds that the mineral are readjusted as that interacts v water. One instance of hydration occurs together the mineral anhydrite reacts through groundwater. The water transforms anhydrite right into gypsum, one of the most usual minerals ~ above Earth.
Another familiar type of chemical weathering is hydrolysis. In the procedure of hydrolysis, a new solution (a mixture of two or an ext substances) is formed as chemistry in rock interact with water. In countless rocks, because that example, sodium minerals interact with water to form a saltwater solution.
Hydration and also hydrolysis add to flared slopes, another dramatic example of a landscape developed by weathering and also erosion. Flared slopes are concave rock formations occasionally nicknamed “wave rocks.” their c-shape is mainly a result of subsurface weathering, in i beg your pardon hydration and hydrolysis wear far rocks in ~ the landscape’s surface.
Living or once-living organisms can likewise be agents of chemistry weathering. The decaying continues to be of plants and also some fungi type carbonic acid, which deserve to weaken and also dissolve rock. Part bacteria can weather absent in order to accessibility nutrients such as magnesium or potassium.
Clay minerals, including quartz, are amongst the most typical byproducts of chemical weathering. Clays make up around 40% of the chemicals in all sedimentary rocks ~ above Earth.
For example, specific kinds of wait pollution rise the price of weathering. Burning coal, organic gas, and also petroleum releases chemicals such as nitrogen oxide and sulfur dioxide into the atmosphere. As soon as these chemicals integrate with sunlight and also moisture, they adjust into acids. They then fall back to earth as mountain rain.
Acid rain swiftly weathers limestone, marble, and other kinds of stone. The results of mountain rain can frequently be checked out on gravestones, making names and other inscriptions impossible to read.
Acid rain has additionally damaged plenty of historic buildings and monuments. For example, in ~ 71 meter (233 feet) tall, the Leshan large Buddha at mountain Emei, China is the world’s biggest statue of the Buddha. That was carved 1,300 years ago and sat unharmed because that centuries. Creative drainage system mitigates the natural process of erosion. Yet in current years, acid rain has actually turned the statue’s sleep black and made few of its hair crumble and also fall.

Weathering by water"s freeze-thaw bike has break-up this rock in two.

Photograph by George F. Mobley, national Geographic


Spheroidal weathering is a kind of chemical weathering that occurs once a rectangle-shaped block is weathered from three sides at the corners and also from 2 sides along its edges. It is also called “onion skin” weathering.

Weathered MountainsThe Appalachian hills in east North America once towered much more than 9,000 meter (30,000 feet) high—taller than Mount Everest! Over numerous years, weathering and erosion have worn castle down. Today, the greatest Appalachian height reaches just 2,037 meter (6,684 feet) high.


chemical compound the reacts with a base to type a salt. Acids can corrode some organic materials. Acids have actually pH levels lower than 7.


precipitation v high levels of nitric and also sulfuric acids. Acid rain deserve to be manmade or occur naturally.


process in which life or once-living organisms contribute to the fragmentation of rocks and also minerals (weathering).


(c. 563-483 BCE) Indian prince, spiritual leader, and also founder that the buddhist religion. Also called Prince Siddhartha and also Gautama Buddha.


process transforms the composition of rocks, frequently transforming them once water interacts through minerals to create various chemistry reactions.


chemical weathering procedure in which the freeze-thaw bicycle of ice cream cracks and also disintegrates rock. Likewise called frost weathering.


type that mineral that is clean and, once viewed under a microscope, has a repeating pattern of atoms and molecules.


process of rocks crumbling because of rain, wind, or other atmospheric conditions. Additionally called mechanical weathering and physical weathering.


C-shaped landform consist of of a concave rock wall formed through weathering and also erosion the subsurface rocks. Likewise called a “wave rock.”


chemical weathering process in i m sorry the freeze-thaw bicycle of ice cream cracks and also disintegrates rock. Also called cryofracturing.


stone marking a person"s funeral place, regularly engraved v the person"s name and dates that birth and also death.


type the sedimentary rock largely made the calcium lead carbonate from shells and skeletons of naval organisms.


process of rocks crumbling because of rain, wind, or various other atmospheric conditions. Additionally called physical weathering.


chemical process of a problem combining with oxygen to adjust the substance"s physical and molecular structure.


process that rocks crumbling as result of rain, wind, or other atmospheric conditions. Likewise called mechanically weathering.


part the a plant that secures that in the soil, obtains water and also nutrients, and often shop food made by leaves.


structure formed as water evaporates indigenous a braided lake or sea. The continuing to be salt is buried by sediments, however eventually pierces through the rock, forming a hill.


type of physical weathering in which a single layer of absent is damaged off. Additionally called edge weathering.

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existing in the tropics, the latitudes between the Tropic that Cancer in the north and the Tropic of Capricorn in the south.


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