At first glance, erosion and weathering appear similar; however, they differ considerably. While weathering involves the gradual deterioration of rocks near the surface, erosion refers to soil displacement by wind or waves.
Chemical weathering occurs when rocks break apart due to water, extreme temperatures, or living organisms. An example is when carbonic acid seeps through underground limestone in Carlsbad Caverns causing cracks to form along its walls, creating massive networks of caves with numerous large openings for passageway.
Physical weathering refers to the gradual breakdown and disintegration of rocks due to factors like erosion and mechanical stress, usually from wind or water forces. Rocks can also break apart due to abrasion and freeze-thaw cycles; over time this process creates sand and gravel formation and breaks down your roof shingles over time.
Thermal stress occurs when different minerals within a rock expand at different rates when heated, creating stresses that weaken it. Freeze-thaw cycles occur when water collects in cracks or crevices in rocks during the daytime and turns to ice at nightfall, taking up more space than previously anticipated and eventually cracking apart its host rock.
Human activities can hasten physical weathering through air pollution; for instance, burning fossil fuels releases chemicals into the atmosphere that react with sunlight and atmospheric moisture to form acids that fall back down as rain to Earth, disguising gravestones illegibly. Animals can also play their part by digging through rocks or trampling upon them.
Chemical weathering is the process by which rock is transformed into another substance with different composition. It typically involves water and chemicals dissolved within it; chemical weathering tends to occur more quickly when temperatures are warm and rocks minerals are soft than surrounding material.
Air pollution from fossil fuels combines with oxygen to form acids that rain down as acid rain, further contributing to weathering of rocks and soil.
Chemical weathering also includes oxidation, where iron in rocks combines with oxygen to form rust that weakens and crumbles the rock structure.
Chemical weathering occurs when water interacts with crystals in rocks to cause their dissolution, such as when granite’s feldspar reacts with it to form clay minerals – this type of weathering is responsible for breaking apart large rocks like mountains and even opening caves; its impact also contributes to the creation of stalactites and stalagmites in limestone caves.
Biological weathering occurs when plants and animals work together to dismantle rocks. Some plants, like lichens and mosses, grow directly onto rocks to produce acid which breaks down minerals while fungi penetrate cracks in rock to release chemicals that aid this process of disintegration.
Roots of certain trees play an essential part in biological weathering. Their roots penetrate deeply into the soil, exerting pressure that weakens and eventually disintegrates rocks, as do ferns and bamboo plants. Furthermore, some fungi produce siderophores which exchange ions with mineral cations in rocks they reside upon to breakdown those minerals that make up those rocks.
Animals also play a vital role in biological weathering by digging or burrowing into the soil, breaking up rock underground, and transporting it up to where physical and chemical weathering are more prominent. Others, like moles, shrews and earthworms can break it apart before transporting it up where physical and chemical weathering are more evident; some, like the piddock shell, even drill holes into rocks to provide shelter from predators and protect themselves.
Weathering occurs naturally, but humans can accelerate its progression in various ways. One such way is through air pollution which emits nitrogen oxide and sulfur dioxide into the atmosphere and reacts with water vapor to form acids which fall down as acid rain, further damaging rocks in its path.
Plants also contribute to weathering by growing roots into cracks in rock formations, eventually pushing open these cracks and eventually prizing apart the rocks. Lichens (combinations of fungi and algae) also erode rocks’ surfaces away, rendering them less resistant to erosion.
People can accelerate the weathering of rocks and minerals through mining, paving over natural landscapes or any activity which removes their protective covering. Even recreational activities like off-road driving can help hasten weathering by increasing friction between them and the ground; weathered rocks such as granitic tors can attract tourists while serving as shrines for local communities.