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U/Pb zircon ages of six rock units from southernmost Brazil were obtained by means of SHRIMP II techniques. The studied rocks occur on either side of the Neoproterozoic contact between a juvenile accreted terrane (the Vila Nova Terrane) and a crustal-reworked belt (the Dom Feliciano Belt). This contact is located in the western portion of the exposed Precambrian rocks in the state of Rio Grande do Sul, Brazil.

Contrasting patterns of U/Pb ages are shown by zircons hosted in metamorphosed basic and granitic rocks of the Cerro Mantiqueiras region and in the post-tectonic Lavras Granite, both located in the Vila Nova Terrane and in the syntectonic crust-derived Cacapava Granite in the Dom Feliciano Belt. Contrasting isotopic characteristics also are supported by Nd and Sr isotopes. For the Vila Nova Terrane, Nd model ages are no older than 1.3 Ga, εNd(740 Ma) values are between +2 and +6 and ⁸⁷Sr …