Geochemistry, zircon U-Pb geochronology and Lu-Hf isotopes of the Manda Saia granite: Petrological affinity and magma source of evolved A-type granites from the Carajas province, southeastern Amazonian craton, Brazil

The Manda Saia granite occurs in the Caraj ' as province, southeastern Amazonian craton, and it is represented by two semicircular intrusive stocks in the Mesoarchean granitoid and greenstone belt sequence of the Rio Maria domain. The stocks are composed of hololeucocratic, red-colored monzo-and syenogranite rocks. Biotite is the main ferromagnesian mineral, and amphibole is rare and was formed later. The rocks are ferroan, calk-alkalic, peraluminous and present a restricted and high SiO2 range (74.80 and 77.70%), high FeOt/FeOt+MgO (0.89-0.98) ratios and enrichment in rare earth elements (REEs, 111-497 ppm), with moderate negative Eu anomalies (0.04-0.63). The plutons are classified as ferroan A-type granites and were formed under moderately reduced to moderately oxidized conditions, similar to those those in the Serra dos Caraj' as suite. They also show affinities with the more evolved members from both the reduced Velho Guilherme suite and oxidized Jamon suite from the Caraj ' as province. The Manda Saia granite has a zircon U-Pb crystallization age of 1866 +/- 10 Ma and is derived from partial melting of the Mesoarchean crust of tonalitic composition, as indicated by strongly negative sigma Hf values (-12 to-18). The emplacement of these plutons is related to extensional tectonics with magma transport at shallow crustal levels.

Automated summary

The Manda Saia granite is an intrusive rock found in the southeastern part of the Amazonian craton, specifically in the Caraj'as province. It consists of two semicircular stocks composed of red-colored granite rocks with high iron and aluminum content, as well as enrichment in rare earth elements. These plutons were formed under moderately reduced to moderately oxidized conditions and show similarities with other suites in the region. The zircon U-Pb crystallization age indicates that the Manda Saia granite was derived from partial melting of the Mesoarchean crust, estimated to have formed around 1866±10 Ma.