Search results
Results from the WOW.Com Content Network
It is usually much less important than chemical weathering, but can be significant in subarctic or alpine environments. [5] Furthermore, chemical and physical weathering often go hand in hand. For example, cracks extended by physical weathering will increase the surface area exposed to chemical action, thus amplifying the rate of disintegration ...
The difference in chemical weathering time can span millions of years. For example, quickest to weather of the common igneous minerals is apatite, which reaches complete weathering in an average of 10 5.48 years, and slowest to weather is quartz, which weathers fully in 10 8.59 years. [5]
Spheroidal or woolsack weathering in granite on Haytor, Dartmoor, England Spheroidal weathering in granite, Estaca de Bares, A Coruña, Galicia, Spain Woolsack weathering in sandstone at the Externsteine rocks, Teutoburg Forest, Germany Corestones near Musina, South Africa that were created by spherodial weathering and exposed by the removal of surrounding saprolite by erosion.
Duricrust is a hard layer on or near the surface of soil.Duricrusts can range in thickness from a few millimeters or centimeters to several meters. It is a general term (not to be confused with duripan) for a zone of chemical precipitation and hardening formed at or near the surface of sedimentary bodies through pedogenic or non-pedogenic processes.
The regolith of a region is the product of its long weathering history; leaching and dispersion are dominant during the initial phase of weathering under humid conditions. [1] Saprolites form in high rainfall regions which result in chemical weathering and are characterised by distinct decomposition of the parent rock's mineralogy. [5]
For example, calcium silicate (CaSiO 3), or wollastonite, reacts with carbon dioxide and water to yield a calcium ion, Ca 2+, a bicarbonate ion, HCO 3 −, and dissolved silica. This reaction structure is representative of general silicate weathering of calcium silicate minerals. [9] The chemical pathway is as follows:
Although sometimes confused with weathering rinds, spheroidal weathering is a different type of chemical weathering in which spherical layers of weathered material progressively develop in situ around blocks of jointed bedrock beneath the Earth's surface, rather than in reworked and transported clasts such as cobbles and boulders. [4] [5]
Tropical weathering is a prolonged process of chemical weathering which produces a wide variety in the thickness, grade, chemistry and ore mineralogy of the resulting soils. The majority of the land area containing laterites is between the tropics of Cancer and Capricorn .