The complex plumbing system registered by clinopyroxenes and olivines in the Itapuvuçu alkaline suite, a satellite of the Jacupiranga complex, Ponta Grossa Arch (Brazil)

Melanocratic basic to ultra-basic alkaline rocks from the Itapuvuçu Alkaline Suite (IAS), a satellite intrusion of the classical Jacupiranga alkaline-carbonatite complex in southeastern Brazil, contain clinopyroxene and olivine macrocrysts that record a complex magmatic history. These mafic minerals, the dominant macrocryst phases in the IAS lithologies are subdivided into distinct crystal populations based on petrographic textures, zoning patterns, mineral chemistry and crystal-melt equilibrium relationships. The identified populations include recycled antecrysts, autocrysts, and domains exhibiting disequilibrium features, each reflecting a different stage in the magmatic evolution of the suite. Detailed characterization of these populations enables the reconstruction of key magmatic processes. Thermobarometric estimates derived from clinopyroxene compositions indicate crystallization under polybaric conditions, supporting a dynamic magmatic system. The evolution of the IAS was driven by multiple episodes of mafic recharge and mixing. Equilibrium assessments between clinopyroxene and melt compositions suggest that local basanite/tephrite magmas—represented by nearby lamprophyric dikes intruding the Jacupiranga Complex—are viable parental melts for the IAS. Moreover, mineral chemistry, whole-rock geochemical signatures, and crystal–melt equilibrium relationships collectively support a genetic link between the IAS and the mildly alkaline series of the Jacupiranga Complex, implying derivation from compositionally similar parental magmas.