What Is Chemical Weathering?

Chemical weathering (chemical weathering) changes in the chemical composition of rocks, called chemical weathering. For example, iron-bearing minerals in rocks are oxidized to red-brown iron oxide by the action of water and chemical weathering air; carbon dioxide and water vapor in the air combine to form carbonic acid, which can dissolve limestone; some minerals swell after absorbing water; water and The mineral effect in the rock formation changes the molecular structure of the original mineral and forms a new mineral. These effects can weaken the rock, reduce the density, or expand the volume, and promote rock decomposition

Chemical weathering (chemical weathering) rock under the action of water, carbon dioxide, oxygen and other factors to change the chemical composition and the formation of new substances. Rock undergoes a series of actions such as the dissolution, hydrolysis, hydration, and oxidation of water and carbon dioxide in it, making certain complex substances simple, while the original non-aqueous and hardly soluble substances become watery and easily soluble. Material, making the rock particles smaller and finer. In general, chemical weathering is dominant in hot and humid regions. ^[1]

Rocks in nature are formed under specific geological conditions, and are relatively stable under high temperature, high pressure, and low free oxygen conditions. Once the rock emerges or approaches the surface, it receives the radiant heat of the sun and interacts with the atmosphere.

The most prominent in chemical weathering is

The geochemical characteristics of rocks are the main factors affecting chemical weathering. Due to the different chemical composition of different rocks,

Chemical weathering of rock masses has a high degree of discontinuity in space, and this discontinuity exists widely on all scales from macro, meso to micro. The macro-structural plane is the main place where chemical weathering occurs; fresh rock blocks in weathered rock bodies are surrounded by corrosion zones that develop along the normal direction of the structural plane and are scattered in rotten rocks in spots. Meso-damages such as micro-crevices are common in all types of rocks; chemical weathering extends from the effective hydraulic voids in different spatial positions in the rock to three-dimensional space, which determines the discontinuity of chemical weathering on the meso-scale. Mineral dissolution occurs preferentially at defect locations with excess surface energy in the crystal, and therefore has significant micro-discontinuities. Due to the discontinuous nature, chemical weathering can increase the water-rock interface and increase the scale and rate of mineral dissolution reactions. Through the expansion of existing damage and the accumulation of residues in the damaged space, chemical weathering has an important role in separating-cracking rock masses, rock blocks, and rock-forming minerals. This effect can cause large-scale detachment of rock masses mainly composed of fresh rocks. Parent rock, and the rock mass deposited at the foot of the slope can be broken down into smaller rock debris or mineral debris under the continued effect of chemical weathering, creating conditions for transport to the water body, thereby greatly promoting slope leveling and landform weight Plastic process. ^[2]