Geophysical Journal | 2003 volume 25 4

The influence of the mineral composition on the electrical properties of some granitoids of the Ukrainian Shield

© S.I. Shepel

The influence of the mineralogical composition of a series of granitoids on their specific electrical resistance (ρ) measured at direct and alternating current (1 kHz) and also on dielectrical permeance (ε) at 1 and 700 kHz is studied. The studied complexes are presented by the granites-diorites of the Ukrainian Shield. The increase of total maintenance of quartz and feld-spar causes the increase of ρ, and decrease of ε of dry and air-dried samples for most groups of rocks. Another picture is established for granitoids of the Krivoy Rog ultradeep borehole which is conditioned by the influence of cataclasis as result of which the degree of breaking rocks increases and accordingly their ρ decreases and ε increases with increasing number highohmmed quartz and plagioclase. The increasing number of lowohmmed ore minerals decreases the specific electrical resistance and increases the dielectrical permeance of individual groups of rocks and also all of them. Equations of linear regressions of the connections between the sums of minerals with logarithmes of ρ and ε for some types of rocks and also for their totality have been calculated.

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