Gutenberg Open


Titelanzeige

Personen: Robyr, M. (Autor) 
Carlson, W. D. (Autor) 
Passchier, Cornelis Willem (Autor) 
Vonlanthen, P. (Autor) 
  
Titel: Microstructural, chemical and textural records during growth of snowball garnet
  
Quelle: Journal of metamorphic geology. Bd. 27. H. 6. Blackwell Publishing Ltd. S. 423 - 437
Erscheinungsjahr:    2009
ISBN / ISSN: 1525-1314
URL der Originalveröffentlichung doi:10.1111/j.1525-1314.2009.00824.x
  
Dokumentart:
Zeitschriftenaufsatz Zeitschriftenaufsatz
Sprache: Englisch
Open Access:
Person der Universität:    Passchier, Cornelis Willem  In UnivIS suchen 
Einrichtung: Institut für Geowissenschaften
DDC-Sachgruppe:    Geowissenschaften
DFG-Fachgebiet: Geologie und Paläontologie
ID: 16326  Universitätsbibliothek Mainz
Hinweis:
Informationen zu den Nutzungsrechten unserer Inhalte Informationen zu den Nutzungsrechten unserer Inhalte
Abstract: The growth history of two populations of snowball garnet from the Lukmanier Pass area (central Swiss Alps) was examined through a detailed analysis of three-dimensional geometry, chemical zoning and crystallographic orientation. The first population, collected in the hinge of a chevron-type fold, shows an apparent rotation of 360°. The first 270° are characterized by spiral-shaped inclusion trails, gradual and concentric Mn zoning and a single crystallographic orientation, whereas in the last 90°, crenulated inclusion trails and secondary Mn maxima centred on distinct crystallographic garnet domains are observed. Microstructural, geochemical and textural data indicate a radical change in growth regime between the two growth sequences. In the first 270°, growth occurred under rotational non-coaxial flow, whereas in the last 90°, garnet grew under a non-rotational shortening regime. The second population, collected in the limb of the same chevron-type fold structure, is characterized by a spiral geometry that does not exceed 270° of apparent rotation. These garnet microstructures do not record any evidence for a modification of the stress field during garnet growth. Concentric Mn zoning as well as a single crystallographic orientation are observed for the entire spiral. Electron backscatter diffraction data indicate that nearly all central domains in the snowball garnet are characterized by one [001] axis oriented (sub-)parallel to the symmetry axis and by another [001] axis oriented (sub-)parallel to the orientation of the internal foliation. These features suggest that the crystallographic orientation across the garnet spiral is not random and that a relation exists among the symmetry axis, the internal foliation and the crystallographic orientation.
   
  
Verfügbarkeit prüfen:    Rechercheportal Mainz: 1525-1314
  KatalogPortal Mainz (inklusive FB 06): 1525-1314
  Elektronische Zeitschriftenbibliothek (EZB): 1525-1314
 


Im   
Impressum