title: Paleoproterozoic high-pressure metamorphism in the northern North China Craton and implications for the Nuna supercontinent.
abstract: The connection between the North China Craton (NCC) and contiguous cratons is important for the configuration of the Nuna supercontinent. Here we document a new Paleoproterozoic high-pressure (HP) complex dominated by garnet websterite on the northern margin of the NCC. The peak metamorphism of the garnet websterite was after ∼1.90 Ga when it was subducted to eclogite facies at ∼2.4 GPa, then exhumed back to granulite facies at ∼0.9 GPa before ∼1.82 Ga. The rock associations with their structural relationships and geochemical affinities are comparable to those of supra-subduction zone ophiolites, and supported by subduction-related signatures of gabbros and basalts. We propose that a ∼1.90 Ga oceanic fragment was subducted and exhumed into an accretionary complex along the northern margin of the NCC. Presence of the coeval Sharyzhalgai complex with comparable HP garnet websterites in the southern Siberian active margin favours juxtaposition against the NCC in the Paleoproterozoic.
authors.affiliation: State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China.|CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Wan
authors.affiliation: Department of Geology, University of Leicester, Leicester LE1 7RH, UK.
authors.forename: Brian F
authors.initials: BF
authors.lastname: Windley
authors.affiliation: State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China.|CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China.|Xinjiang Research Center for Mineral Resources, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
authors.forename: Wenjiao
authors.initials: W
authors.lastname: Xiao
authors.affiliation: Petroleum Exploration and Production Research Institute, SINOPEC, Beijing 100083, China.
authors.forename: Jianyun
authors.initials: J
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China.
authors.forename: Ji'en
authors.initials: J
authors.lastname: Zhang