TDEM (Time Domain Electro-Magnetics) Method

Purpose: The TDEM method is widely used for identifying conductive targets in the subsurface, making it ideal for exploring base metals, graphite, and uranium deposits. TDEM surveys are highly effective in locating these targets by measuring conductivity over time after a magnetic field is applied.

Applications:

Mineral Exploration: TDEM is commonly applied to detect conductive mineral deposits, especially those associated with base metals and graphite.

Uranium Exploration: The method’s sensitivity to conductors makes it valuable for locating uranium deposits, even in deep or challenging environments.

Technical Process: The survey uses large loops of high-current copper wire, powered by a TEM57 transmitter and boosted by TEM67 power modules, to create an electromagnetic field. The PROTEM receiver with a 3D coil captures data, while specialized borehole probes (BH43-3D and MAG43-3D) detect both weak and super-conductive sources. Data is modeled with software like Lamontagne MultiLoopIII and Maxwell to provide a 3D view of subsurface conductors.

Key Uses: TDEM is ideal for locating conductive mineral deposits and can be adapted for both surface and borehole applications, making it versatile across mineral exploration projects.

• Large Loop and Moving Loop TDEM surveys locate conductive targets such as those associated with base metals, graphite and uranium.
• A PROTEM receiver with 3D coil receiving from a TEM57 transmitter boosted by two TEM67 power modules can power large 10-gauge copper wire loops for high currents and relatively short turn-off times.
• Borehole BH43-3D and MAG43-3D EM and Fluxgate probes can detect weak and ‘super conductor’ sources.
• Lamontagne MultiLoopIII and Maxwell software model the 3-component data.
• See also:
  • Borehole Time-Domain EM
  • Large Loop TDEM Surveys for base metals, uranium and graphite