Ržanovo metamorphosed lateritic Fe-Ni deposit, Republic of Macedonia

The Ržanovo deposit is a unique example of metamorphosed lateritic Fe-Ni deposits in the wellknown Vardar ophiolitic belt of the Balkans, where Fe-Ni mineralization is a product of the Early Cretaceous lateritic weathering mantle after Jurassic ultramafic rocks subsequently redeposited into the Cretaceous shallow-water marine basin. As a result, a layer of Fe-Ni ore 30–50 m thick with an average Ni grade of ∼1% was formed at the Ržanovo deposit; this layer is traced for more than 4 km along the strike and 500 m down the dip. At the end of the Late Cretaceous, intense Alpine tectonic faulting and folding resulted in overturning of the initially horizontal ore layer, which is now nearly vertical. The most abundant fissile hematite ore contains 0.70–1.27% Ni, whereas the economically most important massive hematite ore with 0.93–1.49% Ni occurs locally. The major Ni-bearing minerals are magnetite, hematite, chromite, sulfides, talc, chlorite, amphibole, and stilpnomelane.