The southern Pernambuco–Alagoas (PEAL) Domain in the Borborema Province, northeastern Brazil, is a large region characterized by voluminous Cryogenian–Ediacaran (640–580 Ma) calc-alkalic granitic to granodioritic rocks, and minor basement orthogneisses. Field, petrography, geochemistry, isotopic and geochronology studies were conducted on orthogneisses basement within Santana do Ipanema Batholith, southern PEAL Domain to determine their age, petrogenesis, and magmatic setting. The granitic to tonalitic orthogneisses contain abundant mafic microgranular enclaves and exhibit a flat-lying foliation. Biotite, amphibole, titanite, epidote and magnetite are the key mafic minerals. SHRIMP U–Pb zircon age from one sample revealed a Concordia age of 958 ± 10 Ma. Chemically, orthogneisses are metaluminous to slightly peraluminous, calc-alkaline to alkali-calcic, ferroan A-type granite to tonalite. Chondrite-normalized rare-earth and trace element patterns are fractionated, LREE and LILE-enriched, and HREE-depleted. Intensive parameter calculations indicate high-temperature crystallization (∼890 °C) with near-solidus temperature between 700 and 600 °C at a depth of ∼4 kbar. Their Sr–Nd isotopic composition (87Sr/86Sr(t) = 0.7032 to 0.7045; εNd(t) = +2.5 to +3.7 and TDM = 1.1 to 1.3 Ga) suggests derivation from a relatively young lower continental crust. Crustal extension induced sub-continental lithospheric mantle upwelling, which may have driven partial melting of newly created lower continental crust during the Tonian, and fractionation of the melt with little crustal mixing toward ferroan A-type granite geochemistry.