Regolith | EPFL Graph Search

Regolith (ˈrɛɡəlɪθ) is a blanket of unconsolidated, loose, heterogeneous superficial deposits covering solid rock. It includes dust, broken rocks, and other related materials and is present on Earth, the Moon, Mars, some asteroids, and other terrestrial planets and moons. The term regolith combines two Greek words: rhegos (ῥῆγος), 'blanket', and lithos (λίθος), 'rock'. The American geologist George P. Merrill first defined the term in 1897, writing: In places this covering is made up of material originating through rock-weathering or plant growth in situ. In other instances it is of fragmental and more or less decomposed matter drifted by wind, water or ice from other sources. This entire mantle of unconsolidated material, whatever its nature or origin, it is proposed to call the regolith. Earth's regolith includes the following subdivisions and components: soil or pedolith alluvium and other transported cover, including that transported by aeolian, glacial, marine, and gravity flow processes. "saprolith'", generally divided into the upper saprolite: completely oxidised bedrock lower saprolite: chemically reduced partially weathered rocks saprock: fractured bedrock with weathering restricted to fracture margins volcanic ash and lava flows that are interbedded with unconsolidated material duricrust, formed by cementation of soils, saprolith and transported material by clays, silicates, iron oxides and oxyhydroxides, carbonates and sulfates, as well as less common agents, into indurated layers resistant to weathering and erosion. groundwater- and water-deposited salts. biota and organic components derived from it. Regolith can vary from being essentially absent to hundreds of metres in thickness. Its age can vary from instantaneous (for an ash fall or alluvium just deposited) to hundreds of millions of years old (regolith of Precambrian age occurs in parts of Australia, though this may have been buried and subsequently exhumed.) Regolith on Earth originates from weathering and biological processes.

Vertical changes of the Co and Mn speciation along a lateritic regolith developed on peridotites (New Caledonia)

Gabrielle Dublet, Vincent Noel

Because they can host significant amounts of Co, the Mn-oxides are commonly considered as the major Co-bearing mineral species in lateritic environments. However, little is known about the process leading to the formation and/or the weathering of these Co- ...

Pergamon-Elsevier Science Ltd2017