U-Pb provenance fingerprints of metavolcanic-sedimentary successions of the Mineiro belt:Proxies for the continuity of plate tectonics through the Paleoproterozoic  

作　　者：W.Teixeira C.A.Ávila I.A.Dussin E.Bongiolo 

机构地区：[1]Instituto de Geociências,Universidade de São Paulo,Brazil [2]Museu Nacional,Universidade Federal do Rio de Janeiro,Brazil [3]Faculdade de Geologia,Universidade do Estado do Rio de Janeiro,Brazil [4]Programa de Pós-graduação em Geociências,Instituto de Geociências,Universidade Federal do Rio Grande do Sul,Brazil

出　　处：《Geoscience Frontiers》2022年第5期309-335,共27页地学前缘（英文版）

基　　金：support of the Geochronological Research Center(CPGeo)of the University of São Paulo,Brazil;the São Paulo State Research Foundation–FAPESP(2004/15295-7 and 2009/53818-5);the National Council of Technological and Scientific Development–CNPq(5092018/Edital Universal)provided partial funding of the research;the Rio de Janeiro State Research Foundation(FAPERJ)for financial support。

摘　　要：We document new U-Pb detrital zircon LA-MC-ICP-MS data for seven metavolcanic-sedimentary successions and metasedimentary sequences and reassess additional dates of five siliciclastic samples toward their tectonic significance in the context of the Mineiro belt,Southern São Francisco Craton.This belt represents a crustal segment of the 2.47–2.00 Ga Minas Orogen,classically known by its Siderian and Rhyacian juvenile rocks with important implications in the Earth’s geodynamics.The new and compiled detrital provenance constraints unravel the long-lived magmatic and sedimentary history of the studied basins,lasting ca.230–220 Myr.The maximum depositional dates around 2.1 Ga reflect the renewed sediment budget with the subsequent metamorphic episode ca.2.0 Ga.Most of the unmixed relative probability diagrams are consistent with sourcing from the Siderian and Rhyacian arcs of the Mineiro belt,determining a detrital provenance change in time and space for the precursor basins.Alternative potential sources could be the youngest rocks of the Mantiqueira and Juiz de Fora terranes that constitute the other segments of the Minas Orogen,given the age match.The overall detrital fingerprints determine the study basins resumed mainly in Rhyacian fore-arc and/or back-arc settings,i.e.,akin to a subductionrelated system that evolved to a collisional(foreland)environment.Few samples show fingerprints of primary extensional settings,determined by major Archean detrital populations sourced from areas outside the Mineiro belt beside the Paleoproterozoic detritus.The working model considers the collage between the Mineiro belt and the ancient foreland around 2.10 Ga and eventual interaction with other crustal segments of the Minas Orogen,generating the ca.2.0 Ga metamorphism over the metasedimentary samples.The more complete isotopic repository in detrital and igneous zircon grains for the studied supracrustal successions and the associated rocks allows new insights into the Rhyacian–Orosirian dynamics of the Minas orogeny.In

关 键 词：PALEOPROTEROZOIC São Francisco Craton Detrital zircon geochronology Metavolcanic-sedimentary basin 

分 类 号：P542[天文地球—构造地质学] P534.3[天文地球—地质学]