Aluminium, the third most abundant element in the earth’s crust, occurs in nature in combination with silicon and oxygen (i.e. as aluminium silicate). When subject to tropical weathering, aluminium silicate may react to form aluminium hydroxide. Rock containing high concentrations of aluminium hydroxide is called bauxite. This rock is the usual starting material for the production of aluminium....

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Cenozoic world-class bauxite deposits developed on sedimentary sequences of the Parnaíba and Amazon Basins. The Décio pilot mine, excavated in Rondon do Pará deposit, exposes a 3 m thick bauxite-bearing lateritic profile top 350 high plateau. From base to top, this is composed clayey bauxite; porous microcrystalline spherulitic ferro-aluminous duricrust, fragmentary top; as well loose spherulit...

biglar permo-triassic bauxite deposit is located in ~15 km northwest of abgarm, southwest of ghazvin province, west of central iran. it consists of 8 stratiform and discontinuous bauxite lenses lying along the contact of ruteh (permian) and elika (triassic) carbonate formations. petrographically, the bauxite ores exhibit collomorphic-fluidal, pseudo-breccia, pseudo-porphyritic, panidio-morphic-...

Microbial communities in engineered terrestrial haloalkaline environments have been poorly characterized relative to their natural counterparts and are geologically recent in formation, offering opportunities to explore microbial diversity and assembly in dynamic, geochemically comparable contexts. In this study, the microbial community structure and geochemical characteristics of three geograp...