Jiménez Millán, JuanRuiz de Almodóvar Sel, GabrielVelilla, N.2019-06-052019-06-051992http://hdl.handle.net/10272/16350Mangenese lithologies from Oliva de la Frontera area occur in the Cumbres-Hinojales unit (Ossa-Morena South-Central Belt) within a Lower Ordovician age volcanosedimentary sequence. Petrographic study allows to differentiate six Mn-Fe lithologies: Mn-crystal tuffs, Mn-shales, cotfcules, Mn-pyroxenoid rich rocks, braunite layers and hematite layers. Al/(Al+Fe-f-Mn) and Na/(Na+K) discriminating ratios support the above classification. Geologic, mineral, textural and geochemical data provide dues about the mixture process among volcanic, terrigene and chemical materials that originated the protolliths o f the metamorphic manganese lithologiesspaAtribución-NoComercial-SinDerivadas 3.0 Españahttp://creativecommons.org/licenses/by-nc-nd/3.0/es/ManganeseProto!ithsMetamorphic rocksStratiform morphologiesOssa-Morena Zonejournal articleopen access