Geochronology,Geochemistry and Zircon Hf Isotope of Miantian Granodiorite Intrusion in Yanbian Region, Southern Jinlin Province and Its Geological Significance
Liu Jinlong
Sun Fengyue
Lin Bolei
Wang Yingde
Wang Shuo
Hu Anxin
Abstract：This paper presents LA-ICP-MS zircon U-Pb dating,geochemical and Hf isotopic data of the granodiorite from Mian-tian intrusion in Yanbian region,with the aim of constraining its petrogenesis and beginning time of subduction of the Paleo-Pacific plate beneath the Eurasian continent.The Miantian intrusion consists mainly of granodiorite with minor diorite.The LA-ICP-MS U-Pb dating results of zircons from the granodiorite indicate that the intrusion formed in the Early Jurassic (1 77 ± 2 Ma,MSWD=1.13).Geochemically,these rocks fall into the calc-alkaline to high-K calc-alkaline series,with A/CNK ratios of 0.88-1.12,which are sub-aluminous granites,being of the characteristics of I type granitoids,enrichment in LILE (such as K,Ba,Rb),LREE,Th and U,relatively depleted in HFSE (such as Ta,Nb,Ti,P).TheεHf (t )values of the granodiorite vary from ±8.72 to ±12.28,and two-stage model ages (T DM2 )vary from 437 to 663 Ma.These characteristics suggest that the primary magma was derived from the remelting of juvenile crustal materials (Neoproterozoic to Early Paleozoic).It is conclu-ded that granodiorite from Miantian intrusion formed in compressional structure setting similar to volcanic arc which could be related to the subduction of the Paleo-Pacific plate beneath the Eurasian continent.
Keywords：zircon U-Pb chronologyzircon Hf isotopegeochemistryYanbian
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：12( 49-60 )