caa a22 4500 477064329 CHVBK 20180405111408.0 cr unu---uuuuu 170330e19961201xx s 000 0 eng 10.1007/BF02440108 doi (NATIONALLICENCE)springer-10.1007/BF02440108 Detrital glaucophane in graywackes of the Rhenohercynian Harz mountains and the geodynamic implications [Elektronische Daten] [M. Ganssloser, T. Theye, H. Wachendorf] Detrital blue amphibole was found for the first time in two samples of the Famennian section of the South Harz-Selke Graywacke and the Tanne Graywacke (Middle Visean) of the Harz Mountains. Microprobe analyses reveal that the blue amphiboles represent glaucophane with Fe3+/(Fe3++AlVI)=0.22 molar ratio. The minimum pressure required for the formation of glaucophane of this composition is estimated to be approximately 8 kbar. The source area of the detrital glaucophane is assumed to be located between the Northern Phyllite Zone and the Mid-German Crystalline Rise, in areas which have been downfaulted (?subducted) during the Variscan orogeny. The age of blueschist-facies metamorphism in the source area must be of pre-Upper Devonian age. This metamorphic event is significantly older than the Lower Carboniferous high-pressure/low-temperature metamorphism documented in parts of the northern Phyllite zone. Hence, the convergent tectonics connected with blueschist-facies metamorphism is not restricted to the Lower Carboniferous, but can be traced back at least to the early Upper Devonian. These data are in accordance with a southerly directed underplating (?subduction) at the northern margin of the Saxothuringian zone active during at least from early Upper Devonian to Lower Carboniferous. Springer-Verlag, 1996 Harz Mountains nationallicence Northern Phyllite Zone nationallicence Mid-German Crystalline Rise nationallicence Saxothuringian zone nationallicence Detrital glaucophane nationallicence Blueschist-facies metamorphism nationallicence Ganssloser M. Institut für Geowissenschaften der TU, Postfach 3329, D-38023, Braunschweig, Germany aut Theye T. Institut für Geowissenschaften der TU, Postfach 3329, D-38023, Braunschweig, Germany aut Wachendorf H. Institut für Geowissenschaften der TU, Postfach 3329, D-38023, Braunschweig, Germany aut Geologische Rundschau Springer-Verlag 85/4(1996-12-01), 755-760 0016-7835 85:4<755 1996 85 531 https://doi.org/10.1007/BF02440108 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02440108 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ganssloser M. Institut für Geowissenschaften der TU, Postfach 3329, D-38023, Braunschweig, Germany aut NATIONALLICENCE 700 1- Theye T. Institut für Geowissenschaften der TU, Postfach 3329, D-38023, Braunschweig, Germany aut NATIONALLICENCE 700 1- Wachendorf H. Institut für Geowissenschaften der TU, Postfach 3329, D-38023, Braunschweig, Germany aut NATIONALLICENCE 773 0- Geologische Rundschau Springer-Verlag 85/4(1996-12-01), 755-760 0016-7835 85:4<755 1996 85 531 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer