In this paper we studied the temperature dependence of the electrical
resistivity of basalt and granite samples. The electrical resistivity of these
samples were measured in the temperature range from RT to 1000 K. It is
observed that, The electrical resistivity of all investigated samples was
decreased with the increase of temperature. The results showed that, the
behaviour of the electrical resistivity have two conduction regions for basalt
and granite samples. In the first region (RT to 400 K) for basalt and
(RT – 450 K) for granite samples, the electrical resistivity exhibits a slight
decrease. In the second region (400 to 1000 K) for basalt and (450 to 1000 K)
for granite samples, the electrical resistivity exhibit a rapid decrease with the
increase of temperature. The average activation energies of investigated basalt
and granite samples are calculated and discussed.