The effects of saturant salinity and pressure on the electrical resistivity of Hawaiian basalts

• Published in: Geophysical Journal of the Royal Astronomical Society Vol. 65; no. 2; pp. 395 - 405
• Main Authors: Rai, Chandra S., Manghnani, Murli H.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.05.1981
• ISSN: 0956-540X; 0016-8009; 1365-246X
• DOI: 10.1111/j.1365-246X.1981.tb02718.x

ac electrical resistivity of several Hawaiian basalts, saturated with four solutions of varying salinity, is investigated in the hydrostatic pressure range of 0.1 MPa to 0.5 GPa (5 kbar), with pore pressure of nearly 0.1 MPa. At 0.1 MPa, the Archie's empirical relationship holds well for basalts ranging in porosity from < 1 to 30 per cent, and saturated with high salinity solution. Resistivity of saturated basalts increases with pressure. As compared to the data for the low-porosity crystalline rocks reports by Brace & Orange, the resistivity of porous basalts (2–13 per cent porosity) increases less rapidly. The empirical relationship (d log ρ/dP) ~ 1.0 GPa‒1 found for the crystalline rocks also holds for basalts.