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In effect, chemical weathering changes the original set of minerals in the rock into a new set of minerals that is in closer equilibrium with surface conditions. True equilibrium is rarely reached, because weathering is a slow process, and leaching carries away solutes produced by weathering reactions before they can accumulate to equilibrium ...
Chemical weathering of igneous minerals leads to the formation of secondary minerals, which constitute the weathering products of the parent minerals. Secondary weathering minerals of igneous rocks can be classified mainly as iron oxides, salts, and phyllosilicates. The chemistry of the secondary minerals is controlled in part by the chemistry ...
The rate of weathering is sensitive to factors that change how much land is exposed. These factors include sea level , topography , lithology , and vegetation changes. [ 4 ] Furthermore, these geomorphic and chemical changes have worked in tandem with solar forcing, whether due to orbital changes or stellar evolution, to determine the global ...
On the Moon, the spectral effects of space weathering are threefold: as the lunar surface matures it becomes darker (the albedo is reduced), redder (reflectance increases with increasing wavelength), and the depth of its diagnostic absorption bands are reduced [4] These effects are largely due to the presence of nanophase iron in both the agglutinates and in the accreted rims on individual grains.
Case hardening is a weathering phenomenon of rock surface induration.It is observed commonly in: felsic alkaline rocks, such as nepheline syenite, phonolite and trachyte; pyroclastic rocks, as pyroclastic flow deposit, fine air-fall deposits and vent-filling pyroclastic deposits; sedimentary rocks, as sandstone and mudstone.
Abrasion is a process of weathering that occurs when material being transported wears away at a surface over time, commonly occurring with ice and glaciers. The primary process of abrasion is physical weathering. Its the process of friction caused by scuffing, scratching, wearing down, marring, and rubbing away of materials.
Main steps (middle), modification processes (right) and controlling factors (left) of sediment evolution. During transportation from the source area to the basin, detritus is subject to weathering, transporting, mixing, deposition, diagenesis and recycling. This complex set of factors can modify parents lithology both compositionally and textually.
Many explanations have been proposed for honeycomb and other cavernous weathering. These explanations include marine abrasion; wind corrosion; mechanical weathering resulting from short-term temperature variations; chemical weathering of the interior of the rock (core-softening) under a protective crust (case-hardening) followed by mechanical removal of the softened material; biogeochemical ...