Provenance of metasediments from the araxá group in the region of Caldas Novas, Goiás, Central Brazil

Abstract

In the Caldas Novas - Rio Quente region (Goiás State, Brazil) outcrop psammitic, psamo-pelitic and pelitic metasediments related to the Araxá Group. These metasediments have La(N)/Lu(N), La/Sc, Th/Sc, La/Co, Th/Co and Cr/Th rates suggesting that the source were felsic rocks from magmatic arcs. The model ages obtained vary between 1.26 and 1.97 Ga suggesting two sources for these metasediments: a juvenile Neoproterozoic source, and another older source related to paleoproterozoic rocks, as observed in other regions of the Brasília Belt. The U/Pb zircon ages obtained in metasediments from this region are predominantly of Neoproterozoic age (<1.0 Ga), with limited contributions from older sources (> 1.0 Ga). The congruence of these geochronological data with geochemical signatures of analyzed rocks suggest that much of the metasediments from the Araxá Group in the region had as source magmatic arc rocks formed in Neoproterozoic, resulting in the development of forearc basins, in which the studied sequence could probably have been deposited..