Detrital zircon ages from the Palaeoproterozoic Tanque Novo-Ipirá Complex, Itabuna-Salvador-Curaçá Orogen, northern São Francisco Craton, Brazil: records from Kenorland and Columbia supercontinents

The Tanque Novo-Ipirá Complex is an ultra-high-temperature metavolcano-sedimentary succession located in the northern portion of the Itabuna-Salvador-Curaçá Orogen, in the São Francisco Craton, but little is known about the provenance and tectonic significance of these rocks. The Complex is mostly composed of granulite-facies paragneiss containing cordierite, sapphirine, orthopyroxene, clinopyroxene, spinel, sillimanite, garnet, and biotite, along with calc-silicate rocks and kinzigite. Although previously interpreted as an Archaean sedimentary succession, new U-Pb (LA-SF-ICP-MS) data on detrital zircons show that the sedimentary units were deposited during the Rhyacian. From all detrital grains, the age range 2800–2400 Ma is the most abundant, with a peak around 2580 Ma. The second highest age concentration lies in the 2260–1900 Ma cluster, followed by the 2450–2260 Ma and >2690 Ma age ranges. The U-Pb zircon age for an amphibole quartz-feldspar gneiss from the Tanque Novo Complex is 2127±49 Ma, while two metagabbro intrusive into this gneiss yielded age of 2096 ±9 Ma. These results suggest that the metasedimentary succession of the Tanque Novo-Ipirá Complex was deposited between 2120 Ma and 2095 Ma in a foreland to collisional tectonic setting, with implications for understanding the earliest collision stage of the Rhyacian-Orosirian São Francisco-Congo Orogeny in the Columbia Supercontinent.