Química mineral de titanitas de granitos paleoproterozóicos da Província Carajás

Abstract

The Paleoproterozoic Anorogenic Granites of the Jamon, Serra dos Carajás, and Velho Guilherme Suites, part of the Carajás Province, were formed in extensional tectonic settings and display variable crystallization conditions, resulting in differences in oxidation degree and metallogenetic potential. Titanite (CaTiSiO5) can serve as an important petrological and metallogenetic indicator due to its ability to incorporate trace elements and rare earth elements (REE) during crystallization. The geochemical signatures of primary and secondary titanites from Suite Jamon oxidized granites Velho Guilherme reduced granites were analyzed, using studies of morphology, texture, and chemical composition of the crystals, highlighting their relationships with magmatic and hydrothermal processes. Primary titanites in oxidized granites, such as those of the Jamon Suite, are predominantly euhedral to subhedral and richer in Ca+Ti, while in the reduced granites of the Velho Guilherme Suite, they are restricted to the Serra da Queimada Granite. Secondary titanites mainly form through the alteration of ferromagnesian minerals and exhibit enrichment in Al, Fe, Ta, Sn, and W, associated with interaction with hydrothermal fluids, as evidenced by the retention of rare earth elements (Sm+La), (Gd+Yb) and Y.