Spectral Induced Polarization Characterization and Petrophysical Properties of Podiform Chromite Deposits and Their Host Rocks’ Electrical Response: An Experimental Study

Abstract

Geophysical exploration for disseminated chromite deposits has always been challenging because the ore body does not exhibit significant geophysical anomalies. An understanding of petrophysical rock parameters can make the interpretation of geophysical data more accurate. The spectral induced polarization (SIP) method emerged as a promising technique to understand the electrical and petrophysical properties of rocks. In the present study, we tried to acquire the low frequency (0.01–1 kHz) spectral nature of chromite host rock samples, including harzburgite, dunite, and serpentinite, to understand their petrophysical properties. A double Cole–Cole (CC) model was adapted for the interpretation of SIP data. The results confirmed that the chargeability (m) and relaxation time (τ) for ferrochromite were (0.61) and (2.42 s), respectively, and for serpentinized rocks (0.40) and (1.86 s). These values were sufficient to produce anomalies with respect to background. Further, ferrochromite samples exhibited higher resistivity (~500,000 Ω m) with respect to harzburgite, dunite, and serpentinite. The serpentinized rocks showed the highest magnetic susceptibility (3.5 × 10⁻³ SI) followed by harzburgite (2.93 × 10⁻³ SI), ferrochromite (2.60 × 10⁻³ SI) and dunite (0.96 × 10⁻³ SI). The ferrochromite rocks showed the highest density (3.9 g/cm³), followed by harzburgite (3.5 g/cm³), dunite (3.02 g/cm³), and serpentinized rocks (2.7 g/cm³). Acquired results can be considered while using geophysical data to increase accuracy. This study contributes to understanding the electrical and petrophysical parameters of chromite deposits and their host rocks.