Field Investigation of Serpentinite With Induced Polarization and the K-Means Clustering Technique

Abstract

We performed a field induced polarization survey at Rocher du Chateau in the French Alps. This site is characterized by the presence of ophiolites with an outcrop of serpentinites. Serpentinite is characterized by high resistivity (∼0.5–10 kΩ m) and high chargeability (∼20–400 mV V−1) values. We collected two serpentinite core samples for spectral induced polarization measurements conducted in the frequency range 10 mHz–45 kHz, validating the field results. The high chargeability of serpentinite is associated with the production of magnetite during the fluid-rock alteration, as indicated by the high magnetic susceptibility of the core samples (0.0340 SI). Using the laboratory measurements and the K-means clustering technique, we successfully imaged the serpentinite facies and we were able to distinguish blocks of serpentinites embedded in the sedimentary cover. This approach could possibly be used for the seafloor exploration using induced polarization.