Open-system magmatic evolution and crystallization conditions of the Ediacaran shoshonitic rocks from the São João do Sabugi Pluton, Borborema Province, NE Brazil

Abstract The Sao Joao do Sabugi Pluton (SJSP) (∼579 Ma) is one of the most expressive occurrences Ediacaran, syn- to post-collisional shoshonitic rocks in Rio Piranhas-Serido Domain, Borborema Province, NE Brazil. petrography, whole rock and mineral composition this pluton were investigated characterize its open-system magmatic differentiation processes. composed three groups: gabbro-diorite, with clinopyroxene ± orthopyroxene amphibole biotite; monzodiorite, biotite (± pyroxenes); granodiorite, as main mafic mineral. Evidences processes, including partially resorbed metasediment xenoliths, are widespread. These metaluminous, alkali-calcic magnesian, have affinity. They show relative LILE LREE enrichment pronounced negative Nb-Ta anomalies. Major trace element geochemical modeling favors magma by fractional crystallization (56–62%) after crustal assimilation ∼30% local paragneisses schists from Serido Group a relatively stationary chamber at depth, under pressures 5–6 kbar, temperatures ∼800–1,000°C oxidizing conditions. less evolved gabbro-diorite was generated ∼18% modal dynamic partial melting metasomatized mantle source.