MICROFRACTOGRAPHY OF GRANITIC-ROCKS UNDER CONFOCAL SCANNING LASER MICROSCOPY

Scanning laser microscopy, in the confocal mode (CSLM) has been applied to a granitic rock, to characterize its fissure space, The technique provides a unique three-dimensional picture of the rock microfractography. CSLM is unique in observing fine details of the fractographic network (connectivity, tortuosity, etc.), its geometry and its relation to other rock-forming components, The fractographic images with standard fluorescence microscopy are compared with those obtained with CSLM. The examples presented emphasize the advantages of CSLM: three-dimensional visualization of the microfractographic network, crack connectivity, automatic evaluation of direction and slope of fissures. These studies are related to the migration of radio-nuclides in the geosphere, The relations between potentially water-conducting open fissures, and the rock-forming minerals provide a means of modelling the 'radionuclide retardation mechanism', a security factor in their definitive storage in rock masses.