A geochronological 40Ar/39Ar and 87Rb/87Sr study of K-Mn oxides from the weathering sequence of Azul, Brazil Ruffet, G. Innocent, C. Michard, A. Féraud, G. /Beauvais, Anicet Nahon, D. Hamelin, B. GEOCHIMIE INDURATION GEOCHRONOLOGIE DATATION ABSOLUE MINERALOGIE MANGANESE POTASSIUM OXYDE 1996 text https://www.documentation.ird.fr/hor/fdi:010006623 fdi:010006623 Ruffet G., Innocent C., Michard A., Féraud G., Beauvais Anicet, Nahon D., Hamelin B.. A geochronological 40Ar/39Ar and 87Rb/87Sr study of K-Mn oxides from the weathering sequence of Azul, Brazil. 1996, 60 (12), 2219-2232 EN BRESIL PARA