Eluvial deposits

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. 

Figure 2. Types of geological structure 1—anthropogenic deposits 2—alluvial deposits 3—lacustrine-alluvial and alluvial-biogenic deposits 4—eluvial deposits 5—deposits of Pj age.

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... 

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. 

The stratum lithology are argillaceous sandstone, limestone, dolomites, basalt and quaternary loose deposit and the joints and faults are widely distributed in rock bed. The thicknesses of gravel, macadam, sand, sandy clay and muck are 5 m to 8 m in the gully and is less 8 m in the piedmont and local is great 8 m which are eluvial and drifted. They are the dominant factors of debris flow occurrence. 

The alluvial greatly-clastic soils (layer 15) and eluvial loamy and greatly-clastic deposits with clay filler (layers 16, 17) are developed under deposits of the sandy horizon. It is products of destruction of basement rock. Their development has sporadic character in the profile. 

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. 

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