Controlling factors of distribution of major, minor, trace, and rare earth elements in the Dash-Aghel laterite deposit, east of Bukan, West-Azarbaidjan province, NW Iran

The Dash-Aghel laterite deposit is located in ~ 20 km of east of Bukan town, south of West- Azarbaidjan province (NW Iran). This deposit was developed as stratiform semi-continous layers and lenses in the boundaries between dolomites of Elika formation (Triassic) and sandstones of Shemshak formation (Jurassic). Mineralogical studies indicate that hematite, goethite, kaolinite, chlorite, montmorillonite, illite, boehmite, quartz, rutile, and pyrite are major minerals of the lateritic ores. Based on chemical data, this deposit can be divided to three types: (1) ferrite, (2) kaolinitic ferrite, and (3) bauxitic kaolinite. Investigation of correlation coefficients and distribution patterns of elements across a selected profile indicates the effective role of Al and Si in distribution and concentration of elements such as Cr, Sc, Ba, Cs, Ga, Hf, Nb, Ta, Th, and REEs in the ores. Inharmonic distribution of REEs in the studied profile shows an allogenic origin for deposit. The obtained results from geochemical studies suggest that behavior of elements during development of ores is a function of some factors such as change in chemistry of weathering solutions (pH, Eh), deferruginizationferruginization mechanism, sorption, scavenging by metallic oxides and haydoxides, laterization intensity, presence of resistant phases versus weathering, and fixation of neomorph phases. Further geochemical investigations demonstrate that distribution and fixation of REEs in ores were occurred by clay minerals (kaolinite, chlorite, montmorillonite, and illite), boehmite, rutile, zircon, cerianite, bastnasite, and zenotime.