Early Paleozoic arc-accretion in the northern branch of the Proto-Tethys Ocean: New insights from detrital zircon U Pb ages and geochemistry of paraschists from the Kuanping Complex, North Qinling Orogenic Belt, China

The Proto-Tethys Ocean existed from the Neoproterozoic through early Paleozoic during breakup of Rodinia and was closed with subduction accretion numerous East Asian blocks. North Qinling Orogenic Belt is thought to have formed upon closure Kuanping between China Craton Block. However, timing this widely debated Paleozoic. To date, controversy remains as a barrier in understanding ocean-continent configuration process Ocean. best represented by Complex, which northernmost unit consists wide range meta-sedimentary rocks. Here we present systematic study petrology, whole-rock geochemistry geochronology paraschists complex. yield new detrital zircon UPb ages 500 Ma 3584 two main peaks at 798 958 less dominant peak 2460 Ma. Based on our investigations infer that protoliths were dominantly wackes minor litharenites shales maximum depositional 578 Ma, represents different levels sedimentary sequence an arc-related basin. Their clastic input sourced mainly Block, addditions Craton. Combining results previous data, also Complex accretionary wedge assemblage existence late Paleoproterozoic continental nuclei. Initial intra-oceanic Erlangping-Kuanping occurred ca. northward polarity towards nuclei, resulting formation Erlangping island arc rocks basin until During oceanic crust subducted underneath amalgam 500–490 Northward Block beneath consolidated terrane 490–460 their final southern margin 440 marked northern branch sedimentation continued few remaining residual basins 436 Our model suggests part polarity.