Reactivation and enrichment of a Gondwana margin Ni-Cu-PGE-(Te-Au)mineral system during the breakup of Pangea

The lower crustal domains of the Ivrea Zone of NW Italy record the polyphase evolution of a Ni-Cu-PGE-(Te-Au) magmatic sulfide mineral system, which formed during multiple stages over an 80 Myr interval along the NW margin of Gondwana. Between 290-250 Ma, a series of hydrated and carbonated ultramafic alkaline pipes containing Ni-Cu-PGE-(Te-Au) mineralisation was emplaced in the lower continental crust of the Ivrea Zone. Subsequently, at 200 Ma Ni-Cu-PGE mineralisation was associated with emplacement of the La Balma-Monte Capio (LBMC) ultramafic intrusion. The composition and metal endowment of the LBMC reflects interaction and mixing between a deeply sourced juvenile and relatively dry primitive magma, most likely associated with the Central Atlantic Magmatic Province, with localised pods enriched in volatiles, metals, sulfur and tellurium, consistent with the composition of the Permo-Triassic pipes. The scenario depicted here may explain why ore deposits along the margins of lithospheric blocks are not distributed homogeneously along their entire extension but generally form clusters. As mineral exploration is essentially a search space reduction exercise, this new understanding may prove to be important in predictive exploration targeting for new mineralised camps, as it provides a way to prioritise segments with enhanced fertility along extensive lithospheric block margins.