TY - GEN

T1 - Complex Electrical Conductivity of Kimberlites: A Case of North-Eastern Angola

AU - Emelianov, V.

AU - Abramov, V.

AU - Titov, K.

AU - Revil, A.

PY - 2022

Y1 - 2022

N2 - In this paper, we present new data about complex conductivity of kimberlite. Six samples of different facies were taken within Alto Cuilo field in Angola: two hard (porphyric) kimberlites, three kimberlite breccia and one tuff-sandstone with kimberlite material. We also measured the specific surface area and the cation exchange capacity. Based on multi-salinity complex conductivity measurements we obtained the formation factor and the real part of the surface conductivity. We found medium–to–high values of the imaginary conductivity (Induced Polarization, IP) especially for the breccia samples. All studied samples contain ore minerals in minor quantity, so the IP effect can be attributed to both ore mineral or clayey matrix. We found a good correlation between the cation exchange capacity and both the quadrature conductivity and the real surface conductivity, which proves that the IP effect is related to the clayey matrix. We also found a satisfactory correlation between the imaginary conductivity and the surface conductivity. The respective slope (0.015) is typical of clayey sandstones. Considering also the surface conductivity values in the range from 0.013 to 0.16 S/m, we state that the values of electrical properties are typical rater of soils or clayey sandstones than of ingenious rocks.

AB - In this paper, we present new data about complex conductivity of kimberlite. Six samples of different facies were taken within Alto Cuilo field in Angola: two hard (porphyric) kimberlites, three kimberlite breccia and one tuff-sandstone with kimberlite material. We also measured the specific surface area and the cation exchange capacity. Based on multi-salinity complex conductivity measurements we obtained the formation factor and the real part of the surface conductivity. We found medium–to–high values of the imaginary conductivity (Induced Polarization, IP) especially for the breccia samples. All studied samples contain ore minerals in minor quantity, so the IP effect can be attributed to both ore mineral or clayey matrix. We found a good correlation between the cation exchange capacity and both the quadrature conductivity and the real surface conductivity, which proves that the IP effect is related to the clayey matrix. We also found a satisfactory correlation between the imaginary conductivity and the surface conductivity. The respective slope (0.015) is typical of clayey sandstones. Considering also the surface conductivity values in the range from 0.013 to 0.16 S/m, we state that the values of electrical properties are typical rater of soils or clayey sandstones than of ingenious rocks.

KW - electrical conductivity

KW - kimberlites

KW - induced polarization

U2 - 10.3997/2214-4609.202220050

DO - 10.3997/2214-4609.202220050

M3 - Conference contribution

SP - 1

EP - 5

BT - NSG2022 4th Conference on Geophysics for Mineral Exploration and Mining

T2 - Near Surface Geoscience Conference & Exhibition 2022

Y2 - 18 September 2022 through 22 September 2022

ER -