Chemical and mineralogical analyses of a weathering mantle developing on peridotite of the mining area for nickel in Cerro Matoso, Colombia

Four samples were collected at several depths in a weathering mantle develo ping on peridotite, found in a mining area for nickel of Cerro Matoso, abou t 20 km southwest of Monte Libano, Department of Cordoba, Colombia. Samples represent the main stratigraphy of the mantle. Powder X-ray diffractometry , RT Mossbauer spectroscopy, saturation magnetization measurements and conv entional chemical analysis on the whole and chemically treated samples, and on some of their magnetic extracts, were used to give some details of the main occurring mineralogical phases in the mantle, particular of the magnet ic iron oxides.