protore

CONT: On nomme «protore» le minerai normal qui n'est pas modifié par la cémentation et qu'on trouve en profondeur.
CONT: Au Brésil, tous les gisements se situent sur des concentrations primaires de rhodochrosite souvent recristallisés en grenat spessartine. Le profil type comprend de bas en haut : le protore, le minerai sous forme de plaques indurées composées de psilomélane, nsutite et pyrolusite, une zone bréchique et des pisolithes à cryptomélane.
PHR: Protore cherteux, cuprifère, de cuivre-or, sulfuré.

CONT: ... protore ... is mineral material in which an initial but uneconomic concentration of metals has occurred that may by further natural processes be upgraded to the level of ore.
OBS: protore: In older writings, any primary mineralized material too low in tenor to constitute ore but from which ore may be formed through secondary enrichment. As commonly employed today, the rock below the sulfide zone of supergene enrichment; the primary material that cannot be produced at a profit under existing conditions but that may become profitable with technological advances or price increases.
PHR: Cherty, copper-bearing, copper-gold, sulphide protore.