Eluvial processes

Remezov, N. P., 1958. Relation between biological accumulation and eluvial process under forest cover. Soviet Soil Sci, 589. 

The eluvial and alluvial PGM deposits have been processed in the Soviet Union, Canada, Columbia and the United States. Most of these deposits are associated with Alaskan-type ultrafamic rocks, which are, themselves, enriched in PGM, in particular, in the vicinity of... 

Fig. 1. Hypothetical soil profile chat has all principal horizons. Not all horizons shown are present in any given profile, but every profile has some of them. Terms used in diagram Eluviation is the downward movement of soluble or suspended material in a soil from the A horizon to the B horizon by groundwater percolation. The term refers especially, but not exclusively, lo the movement of colloids, whereas the term leaching refers lo the complete removal of soluble materials. Illuviation is the accumulation of soluble or suspended material in a lower soil horizon that was transported from an upper horizon by the process of eluviation. Gleying is soil mottling, caused by partial oxidation and reduction of its constituent ferric iron compounds, due to conditions of intermittent water saturation. Process is also called gleizalion (Adapted from USD A diagram)...

The possible involvement of EMF in weathering of soil minerals was recognized by Hintikka and Naykki (1967), who found that the formation of eluvial horizons in podzols was strongly promoted under fungal colonies of Hydnellum ferrugineum (Fig 14.1). The importance of EMF for the podzolization processes is further discussed by Lundstrom et al (2000). 

Illuvial. Pertaining to the deposition of dissolved or particulate soil material into one area or horizon of the soil from another. This material is transported by the process of eluviation. 

Xerults Epipedon ochric (umbric, molUc). Major processes leaching, eluviation,... 

The use of monazite and xenotime is generally linked to the demand of other economically recoverable elements, e.g., titanium (sphene, rutile, ilmenite), tin (cassiterite), niobium (euxenite), zirconium (zircon) in placer alluvial, fluvial, eluvial, and beach deposits. Rarely has monazite or xenotime occurred in great enough concentration to make it economically recoverable as a primary ore mineral. Nevertheless, there is a considerable worldwide reserve of these minerals which could be processed in the future under more favorable economic conditions. 

These studies seem to bear out the findings of laboratory studies that clay-size mica is more resistant to weathering than sand-size mica. The process of weathering is confounded by eluviation within soil in place and movement by soil material by water and wind, so that interpretations are difficult to prove. 

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