| Title: |
Three-dimensional geoelectrical imaging beyond 1 km depth for mineral exploration : framework of deep electrical resistivity tomography and induced polarization with advanced strategies |
| Authors: |
SEEMSDEEP working grp; Kim, Bitnarae; Deparis, Jacques; Bretaudeau, Francois; Vedrine, Simon; Kamm, Jochen; Autio, Uula; Patzer, Cedric; Heinonen, Suvi; Gance, Julien; Darnet, Mathieu |
| Contributors: |
Institute of Seismology; Department of Geosciences and Geography |
| Publisher Information: |
Oxford University Press |
| Publication Year: |
2026 |
| Collection: |
Helsingfors Universitet: HELDA – Helsingin yliopiston digitaalinen arkisto |
| Subject Terms: |
Electrical properties; Electrical resistivity tomography (ERT); Europe; Geosciences |
| Description: |
Direct current electrical resistivity tomography (ERT) is a widely used geophysical method for near-surface investigations, offering high-resolution imaging for geological, engineering and environmental applications. While traditional ERT surveys typically target depths of 0-200 m, technological advancements have enabled deeper investigations, commonly referred to as Deep ERT. In this study, we explore the practical challenges and methodological improvements associated with Deep ERT, particularly when combined with induced polarization (IP) measurements. Rather than other electromagnetic methods, ERT offers a more straightforward framework for analysing IP effects, which can potentially correlate with the volume fraction of ore minerals. Nevertheless, deep IP investigations are often challenged by weak signal strength and various sources of electromagnetic interference. To address these challenges, we evaluated key strategies including survey planning, high-power current injection, unconventional electrode configurations and advanced signal processing techniques. The adoption of nodal geophysical recording systems eliminates the logistical constraints of cabled multi-electrode setups, improving flexibility and data acquisition efficiency. Additionally, continuous full time-series recording allows for enhanced noise filtering and signal stacking, ultimately increasing the signal-to-noise ratio and extending the effective exploration depth. We demonstrate this methodology through a comprehensive case study conducted at the Koillismaa Linear Intrusion Complex in Finland, where a 3-D Deep ERT-IP survey successfully delineated conductive and chargeable anomalies at depths exceeding 1.5 km. These anomalies closely align with independent gravity and borehole logging data, consistent with the mafic-ultramafic intrusion structures. Our results emphasize the importance of balancing data quality, survey efficiency and spatial resolution in survey design. This work not only provides a robust workflow for the implementation ... |
| Document Type: |
article in journal/newspaper |
| File Description: |
application/pdf |
| Language: |
English |
| Relation: |
This work has been conducted as part of the SEEMS DEEP (Seismic and electromagnetic methods for deep mineral exploration) project that was funded through ERA-MIN3 Joint Call 2021 (National funding agencies: Finland: Business Finland, Grant ID: 640/31/2022; France: ANR, Grant ID: ANR-22-MIN3-0006-02). We want to further acknowledge FLEX-EPOS and Geophysical Instrument Pool Potsdam (GIPP) for providing seismic and electromagnetic instruments.; https://hdl.handle.net/10138/627347; 001664992600001 |
| Availability: |
https://hdl.handle.net/10138/627347 |
| Rights: |
cc_by ; info:eu-repo/semantics/openAccess ; openAccess |
| Accession Number: |
edsbas.A3E8CB97 |
| Database: |
BASE |