An experimental study of permeability and fluid chemistry in an artificially jointed marble

To examine the amount of rock dissolution accompanying changes in joint permeability, deionized water was forced through axially split cylindrical samples of Vermont marble, subjected to a confining pressure of 60 MPa. For freshly polished surfaces, permeability decreased and fluid chemical concentrations increased during the first 50 to 100 hours of fluid flow. For the water-etched surfaces, permeability was not time dependent, and a steady state chemical composition was reached after 20 to 40 hours. A calculation of the steady state chemical concentrations for coexisting calcite and dolomite in deionized water, at a fluid pressure of 10 MPa and a confining pressure of 60 MPa, shows that the steady state values reached in our experiments were supersaturated. -from Authors