Mineralogical and chemical characterization of supergene copper-bearing minerals: Examples from Chile and Burkina Faso

• Supergene copper mineralization (SCM) from Atacama Desert and SW of Burkina Faso. Paragenesis chemical characterization SCM different geodynamic context. The same mineralogy geochemical patterns are observed in both areas. REE study suggests oxidizing conditions to form supergene mineralization. Geological climatic controls involve the genesis these similar. Using optical microscopy, SEM, EPMA LA-ICP-MS, we analyzed characterized textural features Cenozoic Cu-bearing minerals three exotic two situ northern Chile. In addition, their major rare earth elements compositions. We then compared data those obtained Gaoua Cu-Au porphyry district, emplaced during a setting West African craton. mineralization, chrysocolla is dominant copper-bearing mineral, followed by pseudomalachite with minor amount wad. Chrysocolla show distinct features. appears either as black Mn-rich clasts or light-blue green masses, filling fractures coating non-mineralized clasts. Pseudomalachite occurs color bands thin coatings empty spaces. All deposits share some common regard element compositions, i.e. i) range compositions suggesting similar formation ii) strong Ce anomaly indicative oxidant crystallization minerals. Our results reflect for all mining districts lead us propose that areas (i.e. southwestern Faso) underwent geological order preserve exhumation deposit weathering primary sulfides, downward laterally moving solutions finally, arid hyperarid climate prevent mechanical abrasion leaching newly formed