Metamorphic P-T-t Path of Eclogites from Qianliyan Island in the South Yellow Sea and Its Tectonic Implications
Li Min
Han Zongzhu
Xu Hong
Zhao Guangtao
Zhang He
Lai Zhiqing
Abstract：The eclogites in Qianliyan Island,the South Yellow Sea,is important for conducting further research of Dabie-Sulu Orogen.Petrographic and mineralogic studies reveal four main metamorphic stages,including prograde (Stage Ⅰ),eclogite-facies (Stage Ⅱ)metamorphism,and amphibolite-(Stage Ⅲ),greenschist-facies (Stage Ⅳ)retrograde metamorphisms.The metamorphic P-T conditions are estimated as follows:Stage Ⅱ,T=806.3 ℃,P=3.32 GPa;Stage Ⅲ,T=658.68 ℃,P =0.78 GPa;Stage Ⅳ,T<550 ℃,P<0.3 GPa.The SHRIMP U-Pb datings of the zircons from eclogites show that the proto-liths were formed in Neoproterozoic (about 747±19 Ma),the UHP metamorphism happened in Early Triassic (about 241.1± 1.5 Ma),and the amphibolite-facies retrograde metamorphism happened in the end of Triassic (about 205.8 Ma).Using the data mentioned above,metamorphic PTt path of eclogites is constructed.The PTt path shows that the eclogites experienced 2 stages of exhumation and reveals that the Qianliyan uplift is the extension of Sulu Orogen in the South Yellow Sea.
Keywords：the South Yellow Seaeclogitemineral chemistryP-T-t pathSulu orogentectonticsMetamorphic rocks
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：12( 1289-1300 )