Abstract Discontinuous exposures of diamictite (>1000 km) termed the Puga Formation (Fm.) and interpreted as being related to a late Cryogenian glacial event are known in the Paraguay Belt (Brazilian–Pan-African Orogeny) and part of the Amazon craton and Rio Apa Block. These diamictite units and a mixed assemblage of sandstone, conglomerate and claystone were first named the Jangada Group. Recent interpretations have shown that the diamictite of the Puga Formation passes laterally into metasediments of the Cuiabá Group, interpreted as glacially influenced turbidites. The correlative Jacadigo Group in the southern Paraguay Belt includes a thick succession of banded iron formation (BIF) bearing large boulders that have been interpreted as recording glacially influenced sedimentation. The diamictite of the Puga Fm. is overlain by two different carbonate-bearing successions, the Corumbá Group (Cadieus, Cerradinho, Bocaina, Tamengo and Guaicurus formations) in the south and the Araras Group (Mirassol d'Oeste, Guia, Nobres formations) in the north. Evidence of glaciation in the Puga Fm. consists of striated and faceted pebbles and blocks, and dropstones in the turbidites. Sedimentary and geochemical data from the associated carbonate reinforce the interpretation of a glacial origin. C, O and Sr isotope data from the northern Paraguay Belt are consistent with the proposed late Cryogenian age for the Puga Fm. sedimentation.

Abstract The Palaeoproterozoic era was the most important stage of crustal accretion in the South American Platform, being responsible for the development of several magmatic arcs, which represent approximately 35% of the present-day continental crust. The recently mapped Campinorte volcano-sedimentary sequence and associated plutonic rocks represent this Palaeoproterozoic history in the northern Brasilia Belt, central Brazil. The sequence consists of metapsammites and metapelites, with interbedded lenses of gondites and metacherts, as well as rhyolite and pyroclastic deposits. Tonalite, granodiorite and granite crystallized between c . 2.18 and 2.16 Ga, as indicated by U–Pb zircon analyses. Sm–Nd T DM model ages range between c . 2.1 and 2.7 Ga, with ɛ Nd values ranging from −2.14 to +3.36, indicating the dominantly juvenile nature of the original magmas. A LA-ICPMS provenance study of zircon grains from a quartzite sample reveals a single sediment source with Palaeoproterozoic age. The data presented here provide new information on the Palaeoproterozoic juvenile crust of central Brazil and suggest correlation with other Palaeoproterozoic provinces, especially the Birimian Belt in West African Craton and those of the Guiana Shield, thus contributing to reconstruction of the Columbia supercontinent.