Application of Time Domain Induced Polarization (TDIP) Methods Detecting Manganese Minerals

Abstract

Manganese (Mn) is a critical mineral commodity widely used in metallurgy, stainless steel production, and energy-storage technologies. Delineating manganese mineralization in complex carbonate-hosted geological settings requires high-resolution and non-invasive geophysical methods. This study applies the Time-Domain Induced Polarization (TDIP) method to delineate subsurface manganese mineralization in North Central Timor Regency, East Nusa Tenggara, Indonesia. Seven survey lines, each 300 m long with a 5 m electrode spacing, were acquired using a dipole–dipole configuration. The resistivity and chargeability data were inverted using a smoothness-constrained least-squares algorithm implemented in Res2Dinv, while three-dimensional spatial modeling was performed using RockWorks15. The inversion results identify three principal subsurface units based on their resistivity and chargeability responses. The first unit exhibits low chargeability (27.3–354 ms) and low-to-moderate resistivity (2.36–10.1 Ω·m), interpreted as topsoil and overburden of the Maubisse Formation. The second unit is characterized by low-to-moderate chargeability (27.3–463 ms) and very low resistivity (0.27–4.89 Ω·m), corresponding to scaly clay of the Bobonaro Formation. The third unit exhibits high chargeability (354–790 ms) and moderate-to-high resistivity (10.1–43.2 Ω·m), interpreted as nodular manganese mineralization hosted within limestone of the Maubisse Formation. The mineralized zones occur predominantly at shallow depths of 5–10 m, with lateral extents of approximately 50–260 m. The integration of 2D inversion and 3D modeling effectively delineates the geometry and spatial distribution of shallow manganese mineralization, providing a subsurface framework for subsequent exploration activities, particularly trenching and drilling.