40Ar/39Ar Dating of Muscovite from the Guishan Complex in the Tongbai Orogen,Central China, and Its Geological Implications
Qu Wei
Liu Xiaochun
Cui Jianjun
Hu Juan
Li Miao
Abstract：The Guishan complex exposed to the south of the Songpa-Guimei fault in the Tongbai orogen underwent two-stage metamorphism and multiple deformation.However,the timing of metamorphism and deformation of the complex and its relation to the Wuguan complex occurring in the same tectonic position in the Qinling orogen remain poorly constrained.In this paper,4 metasedimentary rocks and 2 metavolcanic rocks from the Guishan complex were performed for muscovite 40 Ar/39 Ar dating.The results suggest that the plateau ages of muscovite range from 306.7± 1.7 Ma (well-preserved muscovite porphyroblasts) to 279.2±2.6 Ma (muscovites overprinted by late deformation).Coupled with published U-Pb zircon data,it is infered that two-stage metamorphism and main thrust deformation of the Guishan complex took place during the Carboniferous,and the reworking of sinistral slid-slip shearing occurred in the Permian.The Guishan and Wuguan complexes have similar rock associations and share the same metamorphic and deformational history.The two complexes constitute a ＞500 km-long Late Paleozoic medium-grade metamorphic belt,which was resulted from the oceanic subduction-accretion prior to the final collision between the North and South China blocks.
Keywords：Tongbai orogenGuishan complex40Ar/39Ar datingLate Paleozoicpetrology
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：12( 247-258 )