The northern boundary of the Proto-Tethys Ocean: Constraints from structural analysis and U–Pb zircon geochronology of the North Qinling Terrane

The North Qinling Terrane, including the Kuanping, Erlangping and Qinling groups, is located in the northern part of the Qinling Orogen. Here we present results from structural analyses of the North Qinling Terrane and its surrounding regions. Three episodes of deformation (D1, D2 and D3) are recognized. The D1 deformation is characterized by NNE-dipping and SSW-dipping penetrative foliations (S1). The S1 foliations are mainly marked by a strong...