The long-term evolution of the continent is often less predictable than in sedimentary basins as remnants are scattered residuals rocks. So, the age of weathering is particularly indicative of the timing of transition of sediments between the source and the basin. The presence of K- bearing Mn oxides offer an incommensurable way to date (K-Ar and ⁴⁰Ar/³⁹Ar methods) and unravel the weathering timing of a deposit area. Therefore, establishing the pathway of their formation in Mn ores through their mineralogy, petrography and geochemistry is of primary order to identify (i) the type of deposit, (ii) the position of these minerals in the paragenetic sequence and (iii) the mineralization process responsible for the concentration of K-Mn oxides.