Disolución de rocas sedimentarias en función del sistema poroso

Abstract

The susceptibility to weathering of eleven carbonate and evaporitic Spanish building rocks were studied by means of dissolution experiments. Mineralogy, geochemistry and porosity of the rocks were also characterized, in order to determine the potential relationships between these properties of the rocks and their dissolution rates. Rock slabs were submerged in a 0.1M HCl solution for 72 h, and the amounts released of Ca, Mg and S were measured, as well as the weight loss of the samples during the acid attack. Alabasters, which presented very low porosity, were dissolved to a lesser extent than limestones and dolostones in the time of the experiment. A significant positive correlation was found for connected porosity with the weight loss of the rocks during dissolution and with the kinetic rate of Ca dissolution. Overall, the results highlight the influence of the porous network in the degradability of building stones by controlling their rate of dissolution.