On the relationship between induced polarization and surface area in metal-sand and clay-sand mixtures

TY - JOUR

T1 - On the relationship between induced polarization and surface area in metal-sand and clay-sand mixtures

AU - Slater, Lee

AU - Ntarlagiannis, Dimitrios

AU - Wishart, De Bonne

PY - 2006

Y1 - 2006

N2 - Induced polarization (IP) measurements were conducted on saturated kaolinite-, iron-, and magnetite-sand mixtures as a function of varying percentage weight of a mineral constituent: 0%-100% for iron and magnetite and 0%-32% for kaolinite. We determined the specific surface area for each mineral using nitrogen gas adsorption, where the porosity of each mixture was calculated from weight loss after drying. We fit a Cole-Cole model (Cole and Cole, 1941) to the electrical data obtained for the magnetite and iron mixtures. In contrast, the kaolinite mixtures showed a power-law dependence of phase-on frequency. The global polarization magnitude we obtained from the Cole-Cole modeling of the iron and magnetite mixtures displays a single, near-linear dependence on the ratio of surface area to pore volume (Sp) calculated for the mixtures. A similar relationship is found using a local measure of polarization (imaginary conductivity at 1 Hz) for the clay-sand mixtures. The Sp appears to be a critical parameter for determining IP in both metallic- and clay-containing soils. This result is not easily reconciled with traditional models of induced polarization.

AB - Induced polarization (IP) measurements were conducted on saturated kaolinite-, iron-, and magnetite-sand mixtures as a function of varying percentage weight of a mineral constituent: 0%-100% for iron and magnetite and 0%-32% for kaolinite. We determined the specific surface area for each mineral using nitrogen gas adsorption, where the porosity of each mixture was calculated from weight loss after drying. We fit a Cole-Cole model (Cole and Cole, 1941) to the electrical data obtained for the magnetite and iron mixtures. In contrast, the kaolinite mixtures showed a power-law dependence of phase-on frequency. The global polarization magnitude we obtained from the Cole-Cole modeling of the iron and magnetite mixtures displays a single, near-linear dependence on the ratio of surface area to pore volume (Sp) calculated for the mixtures. A similar relationship is found using a local measure of polarization (imaginary conductivity at 1 Hz) for the clay-sand mixtures. The Sp appears to be a critical parameter for determining IP in both metallic- and clay-containing soils. This result is not easily reconciled with traditional models of induced polarization.

KW - Iron

KW - Minerals

KW - Nitrogen

KW - Porosity

KW - Sand

KW - Slater Clay

KW - Soil

UR - http://www.scopus.com/inward/record.url?scp=33645664602&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33645664602&partnerID=8YFLogxK

U2 - https://doi.org/10.1190/1.2187707

DO - https://doi.org/10.1190/1.2187707

M3 - Article

SN - 0016-8033

VL - 71

SP - A1-A5

JO - GEOPHYSICS

JF - GEOPHYSICS

IS - 2

ER -