Joint 3D resistivity inversion of ground-based MT and CSEM data to improve resolution for deep mineral exploration
Abstract
The growing demand for critical raw materials to support carbon-neutral energy and transportation systems motivates the exploration of deep-seated (500–4000 m) mineral deposits. Although electrical resistivity is a key parameter for identifying mineralization, imaging these depths remains challenging due to limitations in resolution and nonuniqueness of individual electromagnetic inversions. This study evaluated the potential of joint 3D inversion of magnetotelluric (MT) and controlled-source electromagnetic (CSEM) data to improve subsurface resistivity models. A joint inversion framework was implemented using open-source codes to balance MT and CSEM sensitivities via a relative weight defined by the ratio of the Frobenius norms of their weighted Jacobian matrices. The methodology was applied to a large-scale field data set from northeastern Finland, targeting a deep mafic–ultramafic intrusion at depths exceeding 1.5 km, with regional potential for copper, nickel, platinum-group elements, vanadium, titanium, and iron. Results demonstrated that joint inversion improves model resolution and consistency with known geology and legacy geophysical data compared to individual inversions. These findings highlighted the feasibility and promise of combined large-scale 3D MT–CSEM surveys for deep mineral exploration and provided a scalable framework for future research and commercial applications.
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BibTeX
@article{vedrine2026joint,
title = {{Joint 3D resistivity inversion of ground-based MT and CSEM data to improve resolution for deep mineral exploration}},
author = {Simon Védrine and Cedric Patzer and Francois Bretaudeau and Raphael Rochlitz and Uula Autio and Bitnarae Kim and Jacques Deparis and Fabrice Vermeersch and Jochen Kamm and Mathieu Darnet},
journal = {Geophysics},
year = {2026},
month = sep,
doi = {10.1190/geo-2025-0261},
url = {https://brgm.hal.science/hal-05774014v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Joint 3D resistivity inversion of ground-based MT and CSEM data to improve resolution for deep mineral exploration
AU - Simon Védrine
AU - Cedric Patzer
AU - Francois Bretaudeau
AU - Raphael Rochlitz
AU - Uula Autio
AU - Bitnarae Kim
AU - Jacques Deparis
AU - Fabrice Vermeersch
AU - Jochen Kamm
AU - Mathieu Darnet
PY - 2026
DA - 2026/09/01
JO - Geophysics
DO - 10.1190/geo-2025-0261
UR - https://brgm.hal.science/hal-05774014v1
AB - The growing demand for critical raw materials to support carbon-neutral energy and transportation systems motivates the exploration of deep-seated (500–4000 m) mineral deposits. Although electrical resistivity is a key parameter for identifying mineralization, imaging these depths remains challenging due to limitations in resolution and nonuniqueness of individual electromagnetic inversions. This study evaluated the potential of joint 3D inversion of magnetotelluric (MT) and controlled-source electromagnetic (CSEM) data to improve subsurface resistivity models. A joint inversion framework was implemented using open-source codes to balance MT and CSEM sensitivities via a relative weight defined by the ratio of the Frobenius norms of their weighted Jacobian matrices. The methodology was applied to a large-scale field data set from northeastern Finland, targeting a deep mafic–ultramafic intrusion at depths exceeding 1.5 km, with regional potential for copper, nickel, platinum-group elements, vanadium, titanium, and iron. Results demonstrated that joint inversion improves model resolution and consistency with known geology and legacy geophysical data compared to individual inversions. These findings highlighted the feasibility and promise of combined large-scale 3D MT–CSEM surveys for deep mineral exploration and provided a scalable framework for future research and commercial applications.
SN - 0016-8033
ER -