Podrobnosti záznamu

    Quartz-texture evolution within an orthogneiss structure (Reitzenhain structure, Erzgebirge, SE-Germany), determined by neutron-difraction- The case of fabric isotropization under granitization
Údaj o odpovědnosti
    Alexander Frischbutter, Kurt Helming, Joachim Heinitz, Winfried Voitus
    Frischbutter, Alexander
    Heinitz, Joachim
    Helming, Kurt
    Voitus, Winfried
Zdrojový dokument - seriál
    Zeitschrift für geologische Wissenschaften
    Vol. 24, no. 3-4
    p. 387-402
    9 obr., 2 tab., 17 bibl.
    Anglické resumé
    Zkr. název ser.: Z. geol. Wiss.
Předmětová skupina
    analýza neutronová difrakční
    analýza petrotektonická
    krušnohorské krystalinikum
Geografické jméno
    Loupnické údolí (Most)
Klíčové slovo
Abstrakt (anglicky)
   The quartz texture evolutions combined with increasing anisotropy (from gneiss to pencil gneiss), and increasing isotropy (from pencil gneiss to frictionite) were studied by neutron diffraction. Both situations examine the same event of deformation, starting from the same parent rock, but differs as a result of the level of deformation within the Earths crust. Pencil gneisses in both structural situations have an identical main quartz texture - a dominant c-axes maximum is developed parallel to the medium strain axis (y). From this type of texture a coaxial deformation history can be deduced. Fabric rotations of about 60, combined with the transition from gneiss to pre-pencil-gneiss anmd of 30, combined with the transition from the pre-pencil-gneiss to the pencil state characterize the pencil gneiss evolution.
   One pencil gneiss sample from the frictionite level of deformation is characterized by weak texture asymmetry, which is explained as resulting from superimposed simple shear deformation in the vicinity of the Erzgebirge southern fault. One sample of the mesoscopically untertextured frictionites is isotropic, regarding the quartz texture. The other frictionite sample gave a weak preferred orientation patters, which corresponds with great circle positions of main directions due to block faulting in the Erzgebirge (NE-SW and NW-SE). These great circles are also marked by subordined quartz-c-axes-maxima of the gneisses. The textures may thus represent a composite result of different deformations. There are no residual quartz texture patterns from gneisses detectable is the frictionites. This observation may be better explained by an entire texture breakdown (frictionite concept), than by inhomogenous strain (relic concepts).
   By contrast, faulting produces weak preferred quartz-c-axes orientations, even, if there is no mesoscopic, detactable morphological strain
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
Datum vložení
    20. 2. 2008
Datum importu
    8. 8. 2012