On: “Temperature dependence of the electrical resistivity of water‐saturated rocks” by F. J. Llera, M. Sato, K. Nakatsuka, and H. Yokoyama (GEOPHYSICS, 56, 576–585, May 1990)

Perhaps I missed something in this paper by Llera et al., but the data presented in their Table 1, their saturating fluid resistivity and Archie’s relationship [their equation (1)] do not seem to be consistent. For example, the authors give the saturating solution resistivity [Formula: see text] to be 70 Ω⋅m at 20° C, which is about 60 Ω⋅m at 30° C using the plots of Figure 4, p. 580; and on p. 582, the authors suggest a value of m = 2.0 for the cementation exponent. Sample 1 in Table 1 gives the rock resistivity (ρϕ) at 30° C to be 30 Ω⋅m and the porosity (ϕ) is 4.5 percent; then, using the Archie relationship, we would expect one of the following if a = 1.0.