Age, provenance and tectonic setting of metasedimentary sequences of the Gurupi Belt and São Luís cratonic fragment, northern Brazil: Broadening the understanding of the Proterozoic-Early Cambrian tectonic evolution

摘要: Abstract Geological, U-Pb (detrital zircon), whole-rock Nd isotopes, and geophysical information constrain the timing, provenance, depositional tectonic settings of sedimentary successions from Gurupi Belt (GB) Sao Luis cratonic fragment (SLCF) in northern Brazil. The results, along with published about magmatic events are used to discuss crustal framework regional correlations. We defined following stages sedimentation related Rhyacian Neoproterozoic-Early Cambrian evolution. (1) 2240–2160 Ma –metavolcano-sedimentary sequences formed arc- back-arc basins. (2) 2165–2120 Ma – two syn-orogenic, siliciclastic (turbidite) sequences; oldest (>2149 Ma) a forearc or intra-arc setting, youngest (>2116 Ma) distal system. (3) 2120–2088 Ma post-collisional, continental, basin(s) fluviatile representing foreland system, which was split into sub-basins more recent times. These correlate similar West-African Amazonian cratons, during agglutination continental block pre-Columbia times (>2000 Ma), remained joined through assembly (~1800 Ma) breakup (~1300 Ma) Columbia, being only fragmented Rodinia (~750 Ma). This produced, probably distal, intracontinental effects that led deposition (4) 1130–740 Ma rift passive margin basins; no evidence oceanization is observed, time formations Rokelide West Africa. closure epicontinental sea took place orogeny, represents effect collisional orogenies West-Gondwana at boundary. last event comprises (5)