Mineralogical and morphological features of fractured granitic rock tested under water-rock interaction

Chemical analysis of the Water-rock interaction showed that hydrothermal altered rock contains large amount of fluoride. Considering that alteration has mainly occurred at the fractures’ cleavages, the aim of this paper is to investigate the change of the mineral composition between the cleavages and other parts of the granite surfaces. Scanning electron microscope with energy-dispersive spectrometry has been used in order to identify the change in the morphology and mineralogy of the minerals crystal that occurs on the natural surface of the rock specimens due to water-rock interaction. Second sub aim is to detect the change in the mineral composition between treated and untreated altered granitic rock specimens with water-rock interaction test. However fluoride amount might be in less concentration in biotite, experiments show that the precipitation of fluoride in the cleavages occurs in biotite mineral. This phenomenon might be due to the migration of hydrothermal water causing chloritization of biotite. SEM study of the altered fractured granitic rock indicated deposition of new minerals (fluorite) on the cleavages surfaces after water-rock interaction. One possibility might be due to dissolution of wollastonite.