Eluviation

For an argillic horizon to form, the (coagulated) clay must disperse in the horizon of eluviation before it is transported to the depth of accumulation by percolating water. 

The podzol profile samples were taken from the groundwater catchment areas from humus (A0) eluvial (A) and illuvial (B) horizons and the parent material (C). In coarse-grained sand areas the profile waspoorly developed and mainly 20 cm thick, the thickness in till areas ranged from 40 to 80 cm. 

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... 

The first horizon develops on the surface of the soil and is called the A horizon. Because it has OM deposited on and in it, and is the first to have salts dissolved and eluviated, it is higher in OM and lower in salts than the lower horizons. Clay is eluviated out of this horizon and is deposited lower in the... 

Figure 2.2 also has two other distinctive horizons. The E horizon (which also occurs in Figure 2.4), which stands for eluviated, is characterized by a depletion... 

Fluorine for industrial use is almost exclusively obtained from fluorite. There are many possible fluorite-ore types. It occurs as fissure-fill and manto-replaced types, and in pegmatites, residual/eluvial deposits, carbonates and phosphate deposits. It is a gangue mineral in many base metal deposits, but due to stringent trace metal requirements often can t be economically beneficiated to a saleable product. Most fluorite ores are selectively mined, and ore from some minor vein deposits is then upgraded to a saleable product by sorting. 

Horizons of maximum biological activity, eluviation, or both a2... 

Light-colored horizon of maximum eluviation typified by loss or iron, aluminum, or clay with concentration of resistant minerals, such as quartz. 

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). 

Fig 14.1. Development of the eluvial horizon in a podzol profile of a Scots pine forest in central Sweden (Kroksbo). The soil sample to the right was collected under a dense mycelial mat of Hydnellum ferrugineum while the soil sample to the left was collected at a distance of 20 cm from the Hydnellum mat where no dense fungal mat was present. 

A horizon - high humus content, partially leached of soluble minerals (sometimes called the zone of eluviation)... 

Eluviation. The transportation of dissolved or particulate soil material from one area or specific horizon of the soil to another by the movement of water. 

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. 

---