Simulation of Geochemical Self-Organization: Acid Infiltration and Mineral Deposition in a Porous Ferruginous Limestone Rock

The phenomenon of Liesegang banding finds its most striking natural similarity in the band scenery displayed in rock systems Whereas theoretical modeling studies are extensive in the literature to simulate the reaction-transport dynamics of the medium. experimental simulations in-situ are very scarce We carry out an empirical observation of the evolution of a deposition pattern embedded in a rock A sulfuric acid solution is infiltrated into a porous ferruginous limestone rock by means of an infusion pump This acidization causes the dissolution of the calcite (CaCO(3)) mineral and deposition of calcium sulfate in the form of anhydrite (CaSO(4)) and mainly gypsum (CaSO(4) 2H(2)O), behind the advancing dissolution front We observe the growth of such a deposition pattern and investigate the extent of its resemblance with the well-known Liesegang patterns obtained in the laboratory The composition of the seemingly banded zones is analyzed by powder X-ray diffraction, both qualitatively and quantitatively. The irregular shape of the band zone boundaries seems to be or fractal nature.