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Physical weathering, also called mechanical weathering or disaggregation, is the class of processes that causes the disintegration of rocks without chemical change. Physical weathering involves the breakdown of rocks into smaller fragments through processes such as expansion and contraction, mainly due to temperature changes.
At a temperature of -22 °C, ice growth is known to be able to generate pressures of up to 207MPa, more than enough to fracture any rock. [6] [7] For frost weathering to occur by volumetric expansion, the rock must have almost no air that can be compressed to compensate for the expansion of ice, which means it has to be water-saturated and ...
[1] [2] Climate is a key extrinsic variable, controlling the water to rock ratio, pH, and alkalinity, all of which impact the rate of weathering. [1] The Goldich dissolution series concerns intrinsic mineral qualities, which were proven both by Goldich as well as preceding scientists to also be important for constraining weathering rates.
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.
This figure describes the geological aspects and processes of the carbonate silicate cycle, within the long-term carbon cycle. The carbonate–silicate geochemical cycle, also known as the inorganic carbon cycle, describes the long-term transformation of silicate rocks to carbonate rocks by weathering and sedimentation, and the transformation of carbonate rocks back into silicate rocks by ...
Abrasion is the natural scratching of bedrock by a continuous movement of snow or glacier downhill. This is caused by a force, friction, vibration, or internal deformation of the ice, and by sliding over the rocks and sediments at the base (that also causes an avalanche) that causes the glacier to move.
Exfoliating slabs of granite, on Half Dome in Yosemite National Park, USA. Exfoliating granite is a granite undergoing exfoliation, or onion skin weathering (desquamation).The external delaminated layers of granite are gradually produced by the cyclic variations of temperature at the surface of the rock in a process also called spalling.
Grus is an accumulation of angular, coarse-grained fragments (particles of sand and gravel) resulting from the granular disintegration by the processes of chemical and mechanical weathering of crystalline rocks (most notably granitoids) generally in an arid or semiarid region. [1] Grus sand, when cemented into a sandstone, will form an arkose.