Greenstone belts contain several clues about the evolutionary history of primitive Earth.Here,we describe the volcano-sedimentary rock association exposed along the eastern margin of the Gavi?o Block,named the Northern Mundo Novo Greenstone Belt(N-MNGB),and present data collected with dif-ferent techniques,including U-Pb-Hf-O isotopes of zircon and multiple sulfur isotopes(32S,33S,34S,and 36S)of pyrite from this supracrustal sequence.A pillowed metabasalt situated in the upper section of the N-MNGB is 3337±25 Ma old and has zircon with εHf(t)=-2.47 to-1.40,Hf model ages between 3.75 Ga and 3.82 Ga,and δ18O=+3.6‰ to+7.3‰.These isotopic data,together with compiled whole-rock trace element data,suggest that the mafic metavolcanic rocks formed in a subduction-related setting,likely a back-arc basin juxtaposed to a continental arc.In this context,the magma interacted with older Eoarchean crustal components from the Gavi?o Block.Detrital zircons from the overlying quartzites of the Jacobina Group are sourced from Paleoarchean rocks,in accordance with previous studies,yielding a maximum depositional age of 3353±22 Ma.These detrital zircons have εHf(t)=-5.40 to-0.84,Hf model ages between 3.66 Ga and 4.30 Ga,and δ18O=+4.8‰ to+6.4‰.The pyrite multiple sulfur isotope investigation of the 3.3 Ga supracrustal rocks from the N-MNGB enabled a further understanding of Paleoarchean sulfur cycling.The samples have diverse isotopic compositions that indicate sulfur sourced from distinct reservoirs.Significantly,they preserve the signal of the anoxic Archean atmosphere,expressed by MIF-S signatures(△33S between-1.3‰ to+1.4‰)and a △36S/△33S slope of-0.81 that is indistinguishable from the so-called Archean array.A BIF sample has a magmatic origin of sulfur,as indi-cated by the limited δ34S range(0 to+2‰),△33S～0‰,and △36S～0‰.A carbonaceous schist shows pos-itive δ34S(2.1％-3.5‰)and elevated △33S(1.2％-1.4‰)values,with corresponding negative △36S between-1.2‰ to-0.2‰,which resemble the isotopic composition of Archean black shales and suggest a source from the photolytic reduction of elemental sulfur.The pillowed metabasalt displays heteroge-neous δ34S,△33S,and △36S signatures that reflect assimilation of both magmatic sulfur and photolytic sul-fate during hydrothermal seafloor alteration.Lastly,pyrite in a massive sulfide lens is isotopically similar to barite of several Paleoarchean deposits worldwide,which might indicate mass dependent sulfur pro-cessing from a global and well-mixed sulfate reservoir at this time.

Guilherme S.Teles;Farid Chemale Jr.;Janaína N.ávila;Trevor R.Ireland

Unidade Acadêmica de Minera??o e Geologia,Universidade Federal de Campina Grande,Campina Grande,Brazil;Programa de Pós-Gradua??o em Geologia,Universidade de Brasília,Brasília,Brazil;Programa de Pós-Gradua??o em Geologia,Universidade do Vale do Rio dos Sinos,S?o Leopoldo,Brazil;Research School of Earth Sciences,The Australian National University,Canberra,ACT 2601,Australia;Griffith Centre for Social and Cultural Research,Griffith University,Nathan,Queensland 4111,Australia

地学前缘（英文版）

[1]Guilherme S.Teles;Farid Chemale Jr.;Janaína N.ávila;Trevor R.Ireland-.The Paleoarchean Northern Mundo Novo Greenstone Belt,S?o Francisco Craton:Geochemistry,U-Pb-Hf-O in zircon and pyrite δ34S-△33S-△36S signatures)[J].地学前缘（英文版）,2022(05):190-206

Paleoarchean,Mundo,Greenstone,33S,36S,Gavi,MNGB,pillowed,metabasalt,to+7,juxtaposed,Eoarchean,Jacobina,to+6,to+1,photolytic,barite

Northern,Novo,Belt,Francisco,Craton,Geochemistry,Pb,Hf,pyrite,34S,signatures,belts,contain,several,clues,about,evolutionary,history,primitive,Earth,Here,describe,volcano,sedimentary,association,exposed,along,eastern,margin,Block,named,present,data,collected,dif,ferent,techniques,including,isotopes,multiple,sulfur,32S,from,this,supracrustal,sequence,situated,upper,section,Ma,has,model,ages,between,18O,+3,These,together,compiled,whole,trace,suggest,that,mafic,metavolcanic,rocks,formed,subduction,related,setting,likely,back,basin,continental,In,context,interacted,older,components,Detrital,zircons,overlying,quartzites,Group,are,sourced,accordance,previous,studies,yielding,maximum,depositional,detrital,have,+4,investigation,enabled,further,understanding,cycling,samples,diverse,compositions,indicate,distinct,reservoirs,Significantly,they,preserve,signal,anoxic,Archean,atmosphere,expressed,by,MIF,slope,indistinguishable,called,array,BIF,magmatic,origin,cated,limited,range,to+2,carbonaceous,schist,shows,elevated,values,corresponding,negative,which,resemble,black,shales,reduction,elemental,displays,heteroge,neous,reflect,assimilation,both,during,hydrothermal,seafloor,alteration,Lastly,massive,sulfide,lens,isotopically,similar,deposits,worldwide,might,dependent,pro,cessing,global,well,mixed,sulfate

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