@article{18,
  keywords = {Beishan Orogen, CAOB, eclogite, in-situ monazite U{\textendash}Pb dating, P{\textendash}T{\textendash}t{\textendash}d paths},
  author = {J{\'e}r{\'e}mie Soldner and Pavla {\v S}t{\'\i}psk{\'a} and Karel Schulmann and Chao Yuan and Robert Anczkiewicz and Dariusz Sala and Yingde Jiang and Yunying Zhang and Xinyu Wang},
  title = {Coupling of P{\textendash}T{\textendash}t{\textendash}D histories of eclogite and metagreywacke{\textemdash}Insights to late Ordovician{\textendash}Silurian crustal folding events recorded in the Beishan Orogen (NW China)},
  abstract = {Abstract The Beishan complex is composed of orthogneiss and metagreywacke that both enclose bodies of eclogite and serves as a unique example for comparative petrological study of all these lithologies. The rocks show the earliest regional steep N-S striking fabric (S2) preserved in low strain domains that are reworked by ubiquitous steep N-NE dipping cleavage (S3). The eclogite shows an almost isotropic fabric defined by an M1 assemblage of Grt{\textendash}Cpx{\textendash}Amp{\textendash}Qz{\textendash}Rt{\textendash}Ilm that is locally retrogressed to M2-3 amphibolite facies mineral assemblages, with P{\textendash}T peak at 20{\textendash}21 kbar and 750{\textendash}775{\textdegree}C and retrogression to 2{\textendash}3kbar and 530{\textendash}550{\textdegree}C. The typical mineral assemblage of the host metagreywackes is Bt{\textendash}Ms{\textendash}Pl{\textendash}Qz-Chl{\textendash}Ilm{\textpm}Grt. Rare Al-rich metagreywacke layers are composed of Grt{\textendash}Ky{\textendash}St{\textpm}Sil-And{\textendash}Bt{\textendash}Ms{\textendash}Pl{\textendash}Qz{\textpm}Chl{\textpm}Rt{\textendash}Ilm giving a P{\textendash}T path with peak at 8{\textendash}8.5kbar and  670{\textdegree}C correlated with the S2 fabric and retrogression to  2.5kbar and 525{\textendash}550{\textdegree}C correlated with the S3 foliation. In two eclogite samples, the garnet-whole rock-clinopyroxene Lu{\textendash}Hf isochrons give ages of 461.9{\textpm}1.6 Ma and 462.0{\textpm}6.2 Ma interpreted as reflecting average age of garnet formation, and Sm{\textendash}Nd isochrons give ages of 453.6{\textpm}2.7 Ma and 452.8{\textpm}3.0 Ma interpreted as dating near-peak metamorphism. In metagreywacke, in-situ U{\textendash}Pb dating of monazite gives two groups of ages of 445{\textendash}440 Ma (Mnz cores) and 436{\textendash}429 Ma (Mnz rims), interpreted as reflecting the metamorphic peak and retrogression. Our results show that eclogite was formed during Ordovician by subduction of a continental crust (D1). Eclogite and metagreywacke underwent partly decoupled P{\textendash}T{\textendash}t{\textendash}D paths until their juxtaposition at mid-crustal levels during a first late Ordovician{\textendash}early Silurian D2 shortening. Coupling of their P{\textendash}T{\textendash}t{\textendash}D paths occurred during exhumation in the Silurian and a second and orthogonal D3 shortening event. The data from the Beishan Orogen are consistent with a collisional intra-Gondwanan orogen located south of the Central Asian Orogenic Belt.},
  year = {2020},
  booktitle = {Journal of Metamorphic Geology},
  journal = {Journal of Metamorphic Geology},
  series = {Journal of Metamorphic Geology},
  volume = {38},
  pages = {555-591},
  url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/jmg.12531},
  doi = {https://doi.org/10.1111/jmg.12531},
}