Direct resistivity measurements of core sample using a portable in-situ DC resistivity meter in comparison with HERT data

An indigenous apparatus was devised for measuring the true resistivity of core samples in laboratory or at the drilling site and tested for its efficacy. The true resistivities of selected core samples from a shallow borehole of Brahmaputra alluvium were measured using an in-situ DC resistivity meter and compared with corresponding High-resolution Electrical Resistivity Tomography (HERT) cross section acquired across the borehole site. We find a very good match between the direct measurements and inverse model data of HERT within the limits of resolution. Thus, the present work proves the validity and utility of the resistivity survey in identifying the nature of the sub-surface material and its stratification by measuring the core sample resistivity with the help of in-situ DC resistivity meter.