Image Gallery

Early G50 Fabric Analyser as used by Wilson et al. 2009

Current instrument - G50 v5.4 used by Peternell et al (submitted).

Quartz Mylonite with the [area] selected for fabric analysis on left and with a calcite grain on right. Thin section from Lago di Neves, supplied by Neil Mancktelow (ETH, Zuerich).

Orientation of quartz c-axes from each pixel in the [area] selected in the above thin section. This diagram would have been produced in INVESTIGATOR within 30 seconds.

Location of sites in twinned calcite using the single point analysis technique.

The resulting orientation in the twins within the calcite grain.

c-axis orientation maps of Apatite crystals. The colours in (c) represent the c-axis colatitude values and is given by the geometric quality, black circles with diameter = 1 pixel are equal to 100% geometric quality. (d) represents azimuth (black line) of c-axis orientations. The colour variation indicates the retardation quality. The blue colour from areas where the retardation quality was indeterminable. From a submitted manuscript by Peternell et al.

Mark Peternell, Fabian Kohlmann, Christopher J. L. Wilson, Andrew J. W. Gleadow, Christian Seiler
School of Earth Sciences, The University of Melbourne, Victoria, 3010, Australia

Apatite crystal morphology: influence on crystallographic orientation measurements and its implication for automated fission track analysis

Abstract  Apatite fission track analysis and in particular, computer-assisted fission track recognition is influenced by crystallographic orientation, crystal morphology, cracks, fractures and inclusions. The choice of whether a crystal is chosen for fission track analysis has largely been based on the surface and track etching characteristics. With the use of a fully automated fabric analyser, c-axis orientations can be represented in geometric quality and retardation maps. The c-axis orientation and the related geometric and retardation quality for each pixel of the analysed area can be resolved to 5 μm. These high resolution maps can identify features such as internal fractures, rough crystal faces and impurities related to the sample preparation. The method is not sensitive to smaller crystal cracks, high fission track densities or coating related to the sample preparation. The quantification of the crystal geometrical properties by this method is a step forward to automating the fission track analysis process