Tectonic transition from a syn-rift stage to subsequent post-rift stage is an important mechanism in the evolution of extensional basins.The sedimentary infill records the crustal response to this process.We have obtained new detrital zircon U-Pb and Lu-Hf signatures from the Lower Cretaceous stratigraphic successions encompassing the commonly accepted syn-to post-rift transition boundary,the T4 unconfor-mity,in the Songliao Basin,NE China.These constrain the Songliao Basin's evolution from its center to distal margins,providing insights into the sediment provenance and dispersal pattern over the tectonic transition.Analysis of zircons from the syn-rift(the Shahezi and Yingcheng formations)and immediate post-rift(the Lower and Middle Denglouku Formation)stages reveals Phanerozoic age populations with positive εHf(t)values,which were derived from the proximal juvenile mantle-derived melt origin bedrocks of the Songliao Block.In contrast,the overlying samples from the Upper Denglouku Formation deposited in the subsequent post-rift stage contain exotic and ancient zircon populations with ages of 2.5 Ga&1.8 Ga and complex hafnium signatures,characteristic of a mixed origin.These are interpreted to be transported from distant cratonic terranes via larger drainage networks.It is obvious that the sediment dispersal pattern switched from being a local and hydrologically closed"intraregional"pattern to a"transcontinental"pattern during the transition.The time lag between the development of the T4 uncon-formity and the drainage reorganization also ensures a distinguishable～3 Myr(106103 Ma,Late Albian)transition period of regional extent.During this transition stage,syn-rift faulting was replaced by post-rift thermal subsidence,exhibiting a uniform sag configuration.Our new findings are important for understanding other continental rift basins during syn-to post-rift transition,which often demonstrates a complex interaction between the linkage and integration of sub-basins,and the reorganization of fluvial drainages and catchment systems.

Ying Song;Jianye Ren;Keyu Liu;Dawei Lyu;Xinjie Feng;Yuan Liu;Andrei Stepashko

Shandong Provincial Key Laboratory of Deep Oil&Gas.China University of Petroleum(East China),Qingdao 266580,China;Department of Geology,China University of Petroleum(East China),Qingdao 266580,China;Geology Department,University of Illinois at Urbana-Champaign,United States;Key Laboratory of Tectonics and Petroleum Resources,Ministry of Education,China University of Geosciences(Wuhan),Wuhan 430074,China;CSIRO Energy,Kensington,Western Australia,Australia;Shandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary Minerals,Shandong University of Science and Technology,Qingdao 266580,China;Kosygin Institute of Tectonics and Geophysics,Far Eastern Branch,Russian Academy of Sciences,Khabarovsk,Russia

地学前缘（英文版）

[1]Ying Song;Jianye Ren;Keyu Liu;Dawei Lyu;Xinjie Feng;Yuan Liu;Andrei Stepashko-.Syn-rift to post-rift tectonic transition and drainage reorganization in continental rifting basins:Detrital zircon analysis from the Songliao Basin,NE China)[J].地学前缘（英文版）,2022(03):210-224

unconfor,Shahezi,Yingcheng,Denglouku,bedrocks,intraregional,transcontinental,drainages

Syn,post,tectonic,transition,reorganization,rifting,basins,Detrital,analysis,from,Songliao,Basin,NE,China,Tectonic,syn,subsequent,important,mechanism,evolution,extensional,sedimentary,infill,records,crustal,response,this,process,We,have,obtained,new,detrital,Pb,Lu,Hf,signatures,Lower,Cretaceous,stratigraphic,successions,encompassing,commonly,accepted,boundary,T4,These,constrain,its,center,distal,margins,providing,insights,into,provenance,dispersal,pattern,Analysis,zircons,formations,immediate,Middle,Formation,stages,reveals,Phanerozoic,populations,positive,values,which,were,derived,proximal,juvenile,mantle,melt,origin,Block,In,contrast,overlying,samples,Upper,deposited,contain,exotic,ancient,Ga,complex,hafnium,characteristic,mixed,interpreted,transported,distant,cratonic,terranes,larger,networks,It,obvious,that,switched,being,local,hydrologically,closed,during,lag,between,development,formity,also,ensures,distinguishable,Myr,Ma,Late,Albian,period,extent,During,faulting,was,replaced,by,thermal,subsidence,exhibiting,uniform,sag,configuration,Our,findings,understanding,other,often,demonstrates,interaction,linkage,integration,fluvial,catchment,systems

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