Investigates sedimentation and metamorphism in granulites, suggesting ancient geological processes.
Granulite belts preserve fundamental records of lower-crustal processes and the tectonothermal evolution of ancient orogens, particularly during Paleoproterozoic supercontinent assembly. This study investigates the Novolândia Granulite Belt, Bacajá Domain, SE Amazonian Craton, through integrated field mapping, petrography, U–Pb zircon and monazite geochronology, and whole-rock Nd isotopes. The belt comprises aluminous, felsic, and mafic granulite-facies rocks variably affected by partial melting. Detrital zircon populations from aluminous granulites indicate Paleoarchean to Paleoproterozoic sources (ca. 3.3–2.3 Ga), suggesting sedimentary protoliths derived mainly from reworked ancient crust. Felsic and mafic granulites record the ages of 2744±21 Ma and 2082±7 Ma, respectively, interpreted as the best estimate of protolith crystallization. Metamorphic zircon and monazite ages define a protracted metamorphic event between 2.16 and 2.04 Ga, marked by multiple zircon growth episodes and late monazite crystallization, followed by a younger overprint at 1921±16 Ma. Nd isotopic data yield predominantly negative ε Nd(t) values and Archean-Paleoproterozoic model ages, indicating extensive crustal reworking. The Novolândia Granulite Belt records the prolonged reworking of Archean crust near the Bacajá-Carajás boundary, reflecting a complex history of convergence, magmatism, and granulite-facies metamorphism related to the Paleoproterozoic Columbia assembly, similar to other granulite belts in Amazonian and West-Africa cratons.
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Silva et al. (2026) studied this question.
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