Figure 9. The figure is generated by means of the model ("Appendix A" in Chap. 22, this volume) to demonstrate the time required for the pore water in a 10-cm-wide sediment block (porosity = 0.6, temperature = 25 C) to equilibrate with water in the surrounding fracture system. Initial conditions: C(0,x) = 560 mM; boundary conditions: C(t,0) = C(t,10) = 1220 mM. The curves show the concentration of Cl^- at 0.001, 0.01, 0.04, and 0.129 yr after a brine with a Cl^- concentration of 1220 mM started flowing through the fracture system.