Injection of enriched lithospheric mantle magmas explains the formation of microgranular enclaves in the Rio Jacaré Batholith, Borborema Province, Brazil

The Rio Jacaré Batholith (RJB; 617 ± 4 Ma) is inserted in the Poço Redondo Domain, Sergipano Orogenic System. This batholith formed by monzodiorite, quartz monzonite, and with abundant microgranular enclaves (MEs). MEs vary from black to light gray exhibit globular slightly elongated shapes clear-cut, crenulated, cuspate, or, more rarely, diffuse contacts. They correspond diorites, monzodiorites, monzonites, textural features indicate mixing of magmas, such as compositional zoning plagioclase, inclusion zones plagioclase phenocrysts, poikilitic alkali feldspar, acicular apatite, ocellar quartz. Calculations linear correlations major elements showed that smallest fraction mafic magma involved was 0.43. represent breakdown cooling a injected into cooler felsic magmatic chamber. Emplacement this occurred at different stages crystallization RJB are magnesian metaluminous, affinity shoshonitic series. Ratios for Ba/Nb (> 23), Ba/La 15), Nb/La (0.22–0.69) characteristic magmas generated partial melting an enriched lithospheric mantle source. Batch modeling suggests source rates less than 3% necessary generate similar those MEs.