Interdependence of Mn, Fe, and clay mineral formation on Groote Eylandt, Australia: a model for modern and ancient weathering environments

The genesis of supergene products in the sedimentary Mn deposits on Groote Eylandt (NT, Australia) is the subject of detailed investigations. The tropical/subtropical climate of this locality provides a strongly dynamic weathering environment in which alteration processes operate at higher rates than in temperate regions. Here, the effects of supergene weathering are pronounced in the residual materials and can be identified and evaluated more easily. The results of this study could serve as a guide to geochemical processes in deposits formed in less humid regimes but having comparable mineralogical associations (ie manganese oxides, iron oxyhydroxides, and clays). -from Authors