INVESTIGATIONS OF TEXTURE FORMATION IN GEOMATERIALS BY NEUTRON-DIFFRACTION WITH HIGH-PRESSURE CHAMBERS

This paper suggests a classification of texture in quartzitic rocks. P ossible mechanisms of texture formation and their relation to tectonic processes are discussed. A scheme for the experimental varification o f some methods describing the evolution of deformation structures in g eological materials in dependence on various external conditions (high pressures, temperatures, various loadings, etc.) acting on a sample i s proposed. To investigate '' in situ '' the mechanisms of texture for mation in rocks, high pressure devices are under construction. They wi ll be built of a special T-i - Z(r) alloy, which has zero coherent sca ttering length and therefore is well suited for neutron diffraction in vestigations. Two different devices are proposed. The first one allows neutron diffraction measurements of sample volumes up to 4 cm(3), a h ydrostatic pressure of 1, 5 GPa, a temperature of 300 degrees C, and u niaxial compression up to 50 kN. Pressure, temperature and axial load are measured inside the chamber. Besides, during the experiment, diagr ams, of load, elastic wave velocities and acoustic emission will be re corded. The second chamber is designed to investigate the mechanisms o f texture formation in polycrystal samples (rocks or their imitations) at temperatures up to 800 degrees C and axial compression with a forc e of up to 150 kN.