Extensive crustal melting during craton destruction: Evidence from the Mesozoic magmatic suite of Junan, eastern North China Craton

摘要: Abstract The cratonic destruction associated with the Pacific plate subduction beneath eastern North China Craton (NCC) shows a close relationship widespread magmatism during Late Mesozoic. Here we investigate suite of intrusive and extrusive magmatic rocks from Junan region NCC in order to evaluate role extensive crustal melting related decratonization. We present petrological, geochemical, zircon U-Pb geochronological Lu-Hf isotopic data petrogenesis, timing tectonic significance Early Cretaceous magmatism. Zircon grains basalt show multiple populations Neoproterozoic Paleozoic xenocrystic ranging age 764 Ma 495 Ma as well Jurassic an range 189–165 Ma. dominant population syenite defines three major peaks 772 Ma, 132 Ma 126 Ma. Zircons granitoids including alkali syenite, monzonite granodiorite yield tightly restricted 124–130 Ma representing their emplacement ages. (841–547 Ma) possess eHf(t) values −22.9 −8.4 −18.8 −17.3, respectively. (523–494 Ma) zircons also markedly negative −22.7 −18.0. (134–121 Ma) presented all samples displays −31.7 −21.1, T DM 1653–2017 Ma C 2193–3187 Ma. Accordingly, suggest that parent magma was sourced through Mesoarchean Paleoproterozoic basement rocks. Geochemical on display features similar those arc involving subduction-related components, interaction fluids melts suprasubduction mantle wedge. From presented, propose Mesozoic suites represent lower middle melting, possibly triggered by upwelling back-arc spreading NCC. Intense asthenospheric resulted lithospheric thinning partial delamination Cretaceous, marking one peak decratonization stages