@article{100,
  keywords = {continental crust growth, crustal architecture, Devonian orthogneiss, Mongolian Altai, U{\textendash}Pb geochronology, whole-rock geochemistry},
  author = {Pavel Han{\v z}l and Karel Schulmann and Vojt{\v e}ch Janou{\v s}ek and Ondrej Lexa and Krist{\'y}na Hrdli{\v c}kov{\'a} and Yingde Jiang and D. Burianek and Battushig Altanbaatar and Turbat Ganchuluun and V. Erban},
  title = {Making continental crust: origin of Devonian orthogneisses from SE Mongolian Altai},
  abstract = {Orthogneiss and meta-rhyolite bodies from different crustal levels of the Tseel Terrane in the Mongolian Altai were examined using multidisciplinary approach involving structural geology, whole-rock geochemistry and U{\textendash}Pb zircon geochronology. The orthogneisses form sheet-like bodies parallel with dominant sub-horizontal metamorphic fabric which was heterogeneously verticalized along localized zones of deformation at boundaries of lower and middle crustal domains. Three samples of orthogneisses yielded Late Devonian LA-ICP-MS U{\textendash}Pb zircon ages of 373{\textpm}3, 377{\textpm}5 and 379{\textpm}2 Ma (2σ), which are interpreted as crystallization ages of felsic magmas. The meta-rhyolite displays poorly constrained, older U{\textendash}Pb zircon ages of 380{\textpm}4 and 403{\textpm}5 Ma, which are also considered as intrusive. Whole-rock geochemistry, including relatively little fractionated REE patterns, as well as radiogenic whole-rock Nd and zircon Hf isotopic signatures point to a rather primitive source of the granitic protoliths. The high-K calc-alkaline chemistry and LILE over HFSE enrichments in the NMORB-normalized spider plots indicate an arc-related origin. Juvenile character of the studied rocks was confirmed by Nd and Hf crustal residence ages that are mostly 0.8{\textendash}0.9 Ga. The origin of the metaigneous rocks is interpreted in terms of partial melting of Neoproterozoic to Cambrian magmatic arc-derived material, probably dominated by immature psammitic sediments (graywackes). This study brings important arguments that the orthogneisses do not represent an old crystalline basement previously assumed in the Mongolian Altai. A model is proposed suggesting formation of mature and layered continental crust by syn-orogenic melting of youthful volcanosedimentary wedge and emplacement of sub-horizontal syn-orogenic magmatic sheets at all crustal levels during crustal-scale vertical shortening. The vertical shortening was probably connected to lithospheric-scale extensional event associated with massive heat influx and emplacement of juvenile magmas at the bottom of the crust. It is suggested that this mechanism represents potentially a viable model for cratonization of accretionary systems worldwide.},
  year = {2016},
  booktitle = {Journal of GEOsciences},
  journal = {Journal of GEOsciences},
  series = {Journal of GEOsciences},
  volume = {61},
  pages = {25{\textendash}50},
  url = {http://www.jgeosci.org/detail/jgeosci.206/abstract/},
  doi = {http://dx.doi.org/10.3190/jgeosci.206},
}