摘要：AbstractPlutonic rocks from the Mineiro Belt, Brazil record a delayed onset of the transition from TTG to sanukitoid-type magmatism (high Ba-Sr), starting during the Siderian magmatic lull when little juvenile magma was added to the continental crust. Rocks mostly belong to the calc-alkaline series, meta- to peraluminous and originally “I-type”, meaning that oxidized magmas were formed by partial melting of subducted material. The temporal distribution and apparent secular changes of the magmas are consistent with the onset of subduction-driven plate tectonics due to an increase of the subduction angle and opening of the mantle wedge. New isotopic analyses (Sm-Nd whole rock and Lu-Hf in zircon) corroborate the restricted juvenile nature of the Mineiro Belt and confirm the genetic link between the Lagoa Dourada Suite, a rare ca. 2350 Ma high-Al tonalite-trondhjemite magmatic event, and the sanukitoid-type ca. 2130 Ma Alto Maranhão Suite. U-Pb dating of zircon and titanite constrain the crystallisation history of plutonic bodies; coupled with major and trace element analyses of the host rocks, they distinguish evolutionary trends in the Mineiro Belt. Several plutons in the region have ages close to 2130 Ma but are distinguished by the lower concentration of compatible elements in the juvenile high Ba-Sr suite.Graphical abstractDisplay OmittedHighlights•Latest juvenile TTG to sanukitoid transition in the Palaeoproterozoic starting during the Siderian lull.•Magmatic evolution of high Ba-Sr suite in the Mineiro Belt of Brazil.•Geochemistry and U-Pb analysis of zircon and titanite of several plutons within the Mineiro Belt.•Lu–Hf zircon and Sm–Nd whole rock isotope constraints on the short-lived Palaeoproterozoic crust.•Evolution of the Mineiro belt was driven by mantle extractions with minor crustal assimilation.
关键词：KeywordsenSão Francisco CratonMagmatic lullTTG-Sanukitoid transitionZircon U-Pb-HfTitanite U-PbWhole rock Nd isotopes
