Some evidence for surface ion mobility in rock

摘要

Electrical conductivity measurements have been used to investigate the effect of surface ion mobility in Aspo diorite. Rock tablets were depleted of their ions by leaching, leaving mostly ions in the electrical double layer in the pores. One of the tablets had been ion exchanged with Sr~2+ before leaching, leaving mostly Sr~2+ as the cation in ion exchange positions. The Conductivity through the rock tablets was then measured at increasing pore concentrations of SrCl_2 solutions for the ion exchanged piece and SrCl_2 or NaCl solutions for the others. The Conductivity measurements show a large contribution from the cation layer to the total conductiv- Ity in low salinity pore waters.