Lithosphere extension and upwelling of asthenosphere at post-collisional stage of an orogenic cycle gen-erally induce diverse magmatism and/or associated high-temperature metamorphism.Nevertheless,the intimate coexistence of post-collisional magmatic activity and high-temperature metamorphism is rare.In this contribution,a lithological assemblage composing of diverse magmatic rocks deriving from dis-tinct magma sources and coeval high-temperature metamorphism was identified in eastern Kunlun.Petrography,ages,mineral chemistry and whole-rock geochemistry demonstrated that those intimately coexistent diverse rocks were genetically related to post-collisional extension.The garnet-bearing mafic granulites in Jinshuikou area interior of the East Kunlun Orogenic Belt are mainly composed of garnet,orthopyroxene,and plagioclase,with peak metamorphic P-T conditions of ～ 701-756 ℃ and 5.6-7.0 kbar,representing a granulite-facies metamorphism at 409.7 ± 1.7 Ma.The diverse contemporaneous mag-matic rocks including hornblendites,gabbros and granites yield zircon U-Pb ages of 408.6 ± 2.5 Ma,413.4 ± 4.6 Ma,and 387-407 Ma,respectively.The hornblendites show N-MORB-like REE patterns with(La/Sm)N values of 0.85-0.94.They have positive zircon εHf(t) values of 0.1-4.9 and whole-rock εNd(t) val-ues of 3.9-4.7 but relatively high (87Sr/86Sr)i values of 0.7081 to 0.7088.These features demonstrate that the hornblendites derived from a depleted asthenospheric mantle source with minor continental crustal materials in source.As for the gabbros,they exhibit arc-like elemental signatures,low zircon εHf(t) values(-4.3 to 2.5) and variable whole-rock eNd(t) values (-4.9 to 1.2) as well as high (87Sr/86Sr)i values (0.7068 to 0.7126),arguing for that they were originated from partial melting of heterogeneous lithospheric man-tle anteriorly metasomatized by subducted-sediment released melts.Geochemistry of the granites defines their strongly peraluminous S-type signatures.Zircons from the granites yield a large range of εHf(t) values ranging from-30.8 to-5.1,while the whole-rock samples yield consistent (87Sr/86Sr)i values(0.7301 to 0.7342) and negative εNd(t) values (-10.1 to-12.4).These features indicate that the S-type granites could be generated by reworking of an ancient crust.Taken together,the penecontemporaneous magmatism and metamorphic event,demonstrated the early-middle Devonian transition from crustal thickening to extensional collapse.The post-collisional mantle-derived magmas serve as an essential driving force for the high-temperature granulite-facies metamorphism and anataxis of the crust associ-ated with formation of S-type granite.This study not only constructs a more detail Proto-Tethys evolution process of the eastern Kunlun,but also sheds new light on better understanding the intimate relationship between magmatism and metamorphism during post-collisional extensional collapse.

Qian Wang;Jiao Zhao;Chuanlin Zhang;Shengyao Yu;Xiantao Ye;Xiaoqiang Liu

College of Earth Science and Engineering,Shandong University of Science and Technology,Qingdao 266590,China;Key Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China;State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang 330013,China;College of Oceanography,Hohai University,Nanjing 210098,China;Key Lab of Submarine Geosciences and Prospecting Techniques,MOE,Institute for Advanced Ocean Study,College of Marine Geosciences,Ocean University of China,Qingdao 266100,China

地学前缘（英文版）

[1]Qian Wang;Jiao Zhao;Chuanlin Zhang;Shengyao Yu;Xiantao Ye;Xiaoqiang Liu-.Paleozoic post-collisional magmatism and high-temperature granulite-facies metamorphism coupling with lithospheric delamination of the East Kunlun Orogenic Belt,NW China)[J].地学前缘（英文版）,2022(01):96-113

granulites,Jinshuikou,hornblendites,penecontemporaneous,anataxis

Paleozoic,post,collisional,magmatism,high,temperature,facies,metamorphism,coupling,lithospheric,delamination,East,Kunlun,Orogenic,Belt,NW,China,Lithosphere,upwelling,asthenosphere,stage,orogenic,cycle,erally,induce,diverse,associated,Nevertheless,coexistence,magmatic,activity,rare,In,this,contribution,lithological,assemblage,composing,rocks,deriving,from,dis,tinct,sources,coeval,was,identified,eastern,Petrography,ages,mineral,whole,geochemistry,demonstrated,that,those,intimately,coexistent,were,genetically,related,garnet,bearing,mafic,area,interior,mainly,composed,orthopyroxene,plagioclase,peak,metamorphic,conditions,kbar,representing,Ma,including,gabbros,granites,yield,zircon,Pb,respectively,show,MORB,like,REE,patterns,La,Sm,values,They,have,positive,Hf,relatively,87Sr,86Sr,These,features,derived,depleted,asthenospheric,mantle,minor,continental,crustal,materials,they,exhibit,arc,elemental,signatures,low,variable,eNd,arguing,originated,partial,melting,heterogeneous,anteriorly,metasomatized,by,subducted,sediment,released,melts,Geochemistry,defines,their,strongly,peraluminous,type,Zircons,large,range,ranging,while,samples,consistent,negative,indicate,could,generated,reworking,ancient,Taken,together,event,early,middle,Devonian,transition,thickening,extensional,collapse,magmas,serve,essential,driving,force,formation,This,study,not,only,constructs,more,detail,Proto,Tethys,evolution,process,also,sheds,new,light,better,understanding,relationship,between,during

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