\baselineskip =13pt Orientation distribution function of biotite platelets based on optical, thin sections and $\mu $-CT image analysis in an Outokumpu (Finland) biotite gneiss: Comparison with neutron diffraction texture analysis

Abstract

The results of the neutron diffraction investigation were compared with similar results obtained by analysing more -CT, high resolution photographic and thin section images of a cylindrical sample of the textured Outokumpu (Finland) biotite gneiss. All data were interpreted by means of corresponding orientation distribution function (ODF). Both Rayleigh test of uniformity and Rao's test for homogeneity of the corresponding ODF confirmed the existence of a real anisotropic distribution of mineralogical phases within investigated specimens. Together with the neutron diffraction pole figures, ODF, unambiguously proved the existence of a lattice as well as of the shape preferred orientations of the mineralogical components of the complex Outokumpu gneiss. KEYWORDS: Outokumpu; mica gneiss; neutron diffraction; computed tomography; foliation; lineation; orientation distribution function.